Global optometrist top 200 research ranking

ABSTRACT

Clinical relevance

Clinical optometric practice is underpinned by a rigorous research base, the primary evidence for which is publications in refereed scientific journals. Leading optometrists who publish this work should be identified and celebrated.

Background

This work aims to derive publication metrics of the leading optometric researchers worldwide.

Methods: An extensive global search was conducted to discover leading optometric researchers; 480 names were identified. A custom-designed bibliographic search tool was developed to interrogate the Scopus database (Elsevier) and extract publication metrics using the unique Scopus Author Identifier number for each optometrist. On 13 January 2021, the full list was reduced to 200 optometrists (the ‘Top 200’) ranked by h-index – the ‘Global Optometrist Top 200 Research Ranking’. The output from the custom tool automatically updates every 24 hours and is available at www.optomrankings.com.

Results

The Top 200 have h-indices ranging from 20 to 67 and have published between 28 and 440 papers. Sixty one (30.5%) are women. Konrad Pesudovs has the highest h-index (67) and citations (51,193). The most prolific author is Robert Hess (442 papers). David Piñero is publishing at the fastest rate (17.6 papers per year). The Top 200 work in 13 nations, of whom 172 (86.0%) work in four nations: USA – 76 (38.0%), Australia – 43 (21.5%), UK – 41 (20.5%) and Canada – 16 (8.0%). Of the 72 institutions represented, the University of California, Berkeley, USA is home to the most Top 200 optometrists (17) and has the highest combined h-index of Top 200 optometrists (132).

Conclusions

The optometric profession is supported by a robust research base, prosecuted by a large international cohort of optometric researchers who publish extensively on a broad range of ophthalmic issues and whose work is highly cited. The 200 most impactful optometrists in the world are identified.

KEYWORDS:

• Citations
• global optometrist research ranking
• h-index
• publication metrics

Introduction

Optometry has evolved from humble beginnings as a profession of refractionists and spectacle sellers into a comprehensive science-based and clinical discipline, driven by rigorous fundamental and applied research.¹ Critical to this research effort that underpins the profession is the work and publications of optometry-trained academics, most of whom are based at leading universities around the world.

There are many ways of analysing the output of scholarly publications of individuals. The most basic measure is the total number of papers that an individual has published. However, the association between quantity and quality of publications is unclear, with some arguing that the pressure to publish pushes down quality,² and others suggesting that a more prolific output is associated with higher quality publications.³

Of growing interest over the past two decades has been the concept of publication metrics, which can be generated with the assistance of computer-based bibliographic search engines. Using such tools, it is possible to quantify the number of times that given scientific papers have been cited by others. The underlying assumption is that there is a direct association between the number of citations and the quality of the work, a view which is strongly supported by some bibliometric researchers,⁴ although disputed by others.⁵ Overall, citation analysis is considered to be a useful objective tool for evaluating the impact of scholarly articles, and by extension, the excellence of those who write them.

The current ‘gold standard’ method of analysing the impact of the publications of an author is to determine the ‘h-index’, suggested in 2005 by Jorge E Hirsch⁶ (hence the ‘h’), which combines measures of quantity (number of papers) and quality (number of citations) in a single metric. The h-index of an author is defined as the maximum value of h, such that the author has published h papers that have each been cited at least h times.⁶ Other metrics can also be applied; for example, the m-ratio assesses the progressive, rather than cumulative, performance of an author (m-ratio = h/number of years publishing).⁷ Yet another example is the g-index, which accounts for citations to papers above the h-index, thereby giving more weight to highly cited articles (‘g’ is the highest number of papers that together have received g² or more citations).⁷

In the profession of optometry, previous bibliometric studies have documented the academic performance of Australia-trained optometrists,^8,9 as well as that of authors in the associated optometric sub-disciplines of contact lenses,^10–14 dry eye,¹⁵ binocular vision¹⁶ and visual therapy.¹⁷ Bibliometric data have also been used to reflect upon the research standing of expatriate British optometrists¹⁸ and the impact of optometric journals.^19–21

The editor of Clinical and Experimental Optometry, who is also the lead author of this paper (NE), recently published an editorial in this journal describing an updated analysis of the most highly cited Australia-trained optometrists.⁹ That analysis was purposely parochial; however, the overseas-based optometric co-authors of this work (PBM, LWJ and JJN) approached the lead author suggesting that this analysis be expanded so as to provide an international, non-sub-discipline-specific citation analysis of all optometrists, as this has never been previously reported. The aims of such an analysis would be to (a) identify and celebrate optometrists worldwide who are leading the profession by way of published research, and (b) establish a global benchmark for individual excellence in optometric research publication. This paper therefore represents the product of an international collaboration that has sought to achieve these aims.

Methods

The following approach was adopted for quantifying and ranking the publication metrics of optometrists with outstanding publication records.

Choice of bibliometrics search engine

Three search engines widely used to assemble publication metrics are Scopus (Elsevier), Web of Science (Clarivate) and Google Scholar (Google). Scopus was used in this analysis for the simple reason that it was readily available to all authors of this work. Although the three above-mentioned search engines use different paradigms for assembling publication metrics, and yield slightly different results for a given individual,^8,22 the use of a single search engine can be expected to yield valid comparative results, which is the key aim of this work.

Identification of optometrists with strong publication records

The four optometric authors of this work (NE, PBM, LWJ and JJN) are highly active, senior academics and have all been publishing scientific papers in optometry for between 21 and 44 years; accordingly, they are intimately familiar with the academic landscape in their respective countries of Australia, UK, Canada, and USA. Having travelled and collaborated extensively, they also have a good appreciation of international academic optometry.

Based on this personal knowledge and experience, the authors sought to identify optometry-qualified researchers around the world likely to have strong publication metrics. In the course of this search, which commenced in September 2020, a preliminary analysis of the citation metrics of all optometrists being considered was undertaken to ascertain if they met the screening threshold of a Scopus h-index ≥ 15.

To supplement the personal knowledge of the authors, strategies adopted to identify optometrists worldwide likely to have high publication metrics included scrutiny of faculty lists from optometry schools in countries around the world,²³ inspecting lists of learned international optometric and vision science research organisations, evaluating optometric organisational awardee lists for recipients recognised for their scholarly work, and conducting secondary searches based on author names discovered during primary searches.

Another strategy was to email optometric colleagues from countries in different regions of the world, soliciting the names of optometrists likely to be included in a listing of leading research optometrists. Specifically, assistance was sought in relation to countries and regions from where optometric research is known to take place, including the Antipodes (Australia and New Zealand), Asia (Hong Kong, India, Malaysia, Singapore, and South Korea), continental Europe (Germany, Republic of Ireland, The Netherlands, Portugal, Spain, and Scandinavia) the Middle East (Israel, Qatar, and Saudi Arabia), North America (Canada and the USA), and the United Kingdom. Less attention was directed towards countries and regions where optometric research is not well established, such as China, Russia, Japan, South America, and Africa; nevertheless, all nations were considered, and all suggested names were screened for inclusion in the listing.

An alphabetical listing was compiled of the full names, countries, and institutions of all optometrists discovered. Google Sheets (Google) was used to share the list on-line between the authors of this work, so as to avoid duplication and assist ongoing searching. This above process continued until a comprehensive list was assembled and no more new names were being found; the final list contained 480 names.

Every author on the Scopus database has a unique identifier (ID), called the ‘Scopus Author ID number’. The Scopus Author ID numbers corresponding to all 480 names listed were accessed manually from the Scopus website (www.scopus.com). In the few instances where it was discovered that optometrists had been assigned multiple Scopus Author ID numbers, an application was made to merge these via the dedicated Scopus on-line ‘Author Feedback Wizard’; all such requests were actioned, resulting in a single Scopus Author ID number for each optometrist.

Development of an automated bibliometrics extraction tool

An automated bibliometrics extraction tool was custom-written for this exercise; this tool employed the Scopus Author ID number as input and utilised the Scopus Application Programming Interface (API) to retrieve the desired data. The Python-based API-Wrapper, ‘pybliometrics’,²⁴ facilitated interaction with the Scopus API, enabling extraction of the required data.

A script was written to (a) tabulate the following metrics for each author in a single row: h-index, number of papers, number of citations, number of co-authors, and the year of first and last paper published, (b) arrange the rows of authors in rank order of h-index, and (c) resolve ties according to the tie-break hierarchy outlined below. The script runs automatically once every 24 hours, therefore updating all metrics and rankings on a day-to-day basis.

Constructing the global optometrist top 200 research ranking

The citation metrics of all 480 optometrists identified as having a strong publication record were tabulated in rank order from highest to lowest h-index by the automated bibliometrics extraction tool, as described above. It had become apparent towards the latter phase of the search that the names of optometrists who had not been discovered during the earlier rounds of searching, but were later found, generally had lower h-indices. This was not unexpected; it was evident from inspection of the full listing that lower h-indices were associated with a much greater number of optometrists who had produced fewer publications, and were perhaps less well known.

A decision was therefore made to limit the tabulation to 200 optometrists with the highest h-indices (the “Top 200”); this listing is designated the ‘Global Optometrist Top 200 Research Ranking’. The lowest h-index on this listing is observed to be 20, and in fact there are a number of optometrists with h = 20 who rank lower than 200 as determined by the tie-breaking protocol (see below). The decision to list 200 optometrists was thought to represent a reasonable balance between (a) being sufficiently constrained so as to minimise the risk of missing optometrists who should be featured in a listing of leading optometric researchers with an especially strong track record of publishing, versus (b) not being too constrained in order to be as inclusive as possible.

On the census date of 13 January 2021, a version of the Global Optometrist Top 200 Research Ranking was transferred to a fixed (non-updating) spreadsheet, which was used for (a) tabulation of the listing, shown in the Appendix, and (b) analysis of the bibliometric data in the Appendix using descriptive statistics such as counts, ranks, means, medians, and standard deviations, with the aid of the Excel pivot table and statistical analysis functions (Microsoft).

Further to the listing in the Appendix, the authors have committed to maintain a constantly updating version (refreshed every 24 hours) of the Global Optometrist Top 200 Research Ranking,²⁵ which is freely available online from a dedicated website (www.optomrankings.com) (see Discussion).

Designating location

The location (country and institution) attributed to each optometrist pertains to where the optometrist is currently working, or was last engaged in active research before retiring, pursuing a different course in life unrelated to research, or dying. Although ‘institution’ is one of the data fields automatically extracted from the Scopus database, inspection of this output revealed that some institution designations were not in agreement with the criteria noted above. Accordingly, the Scopus-designated institutions of all those listed were verified manually with reference to current locations as found on the internet for each individual, and adjustments made as required. A country-specific h-index was determined for the Top 200 optometrists for each country (the h_CO-index) and this was used to rank countries with at least three Top 200 optometrists.

Some institutions have changed their name one or more times; perhaps the most exaggerated example of this is Marshall B Ketchum University, which was previously known by the name Southern California College of Optometry until 2013, and prior to this by eight other names since its inception in 1904.²⁶ All institutions in the Appendix are listed by their current name. In some cases, a given institution was described under different names or different versions of the same set of words in the name (e.g. University of Bradford versus Bradford University); the official or most frequently used version of the name for that institution was adopted for all optometrists currently or previously working there. All institutions are designated at ‘university level’, rather than college, school, department, laboratory, or section level. An institution-specific h-index was determined for the Top 200 optometrists (the h_IN-index) for each institution and was used to rank institutions with at least three Top 200 optometrists.

Breaking ties

The order of those in the Global Optometrist Top 200 Research Ranking is by descending value of h-index (going down the table); however, many optometrists have identical h-indices, so ties need to be broken in accordance with a hierarchy that reflects level of achievement. Ties of h-index are broken according to the reverse order of the year-span of publishing, the rationale being that attaining an identical h-index more quickly is a higher-level achievement. For those with the same h-index and year span of publications, ties are broken by total number of citations; if these three measures are identical, ties are broken by total number of papers.

Annotating winners of optometric research awards

Annotations are included alongside the names of optometrists in the Appendix who have received major awards from the following peak optometry-led organisations: Optometry Australia, the American Academy of Optometry, the Polytechnic University of Catalonia (Spain), the British Contact Lens Association, and the International Society for Contact Lens Research – the last two being multidisciplinary organisations, each with a majority of members being optometrists.

Results

As can be seen from the Appendix, the Top 200 have h-indices ranging from 20 to 67 and have published between 28 and 442 papers. There are three optometrists with h ≥ 60; nine with h = 50–59, 25 with h = 40–49, 49 with h = 30–39 and 114 with h = 20–29. Sixty one of the Top 200 (30.5%) are women, although there appears to be little diversity in race or ethnicity (determination of gender, race, and ethnicity were made based on perceptions of the authors).

The research interests (determined from their respective websites), titles of the most highly cited papers,^27–36 and number of citations to each of these papers for the 10 optometrists listed in the Appendix with the highest h-indices are provided in Table 1.

Table 1. Research interests and most highly cited papers of the top 10 ranked optometrists.

Rank	Name	h-index	Research interests	Title of most highly cited paper [number of citations]
1	Konrad Pesudovs	67	Ophthalmic outcomes research; developing measures of quality of life relating to vision and eyecare; understanding the global burden of disease.	Disability-adjusted life years (DALYs) for 291 diseases and injuries in 21 regions, 1990–2010: A systematic analysis for the Global Burden of Disease Study 2010^27 [5,305 citations]
2	Robert Hess	64	Psychophysics of human perception; analysis of visual information in the visual cortex in healthy and amblyopic eyes.	Contour integration by the human visual system: Evidence for a local “association field”^Citation28 [1,177 citations]
3	Dennis Levi	61	Computational modelling and brain imaging to understand neural mechanisms of normal vision and in amblyopia.	Crowding – An essential bottleneck for object recognition: A mini-review^Citation29 [578 citations]
4	Gerald Westheimer	57	Optics and the eye; retinal and central processing of spatial visual information; spatial, temporal and stereoscopic acuity of human vision.	Improvement in visual sensitivity by changes in local context: Parallel studies in human observers and in V1 of alert monkeys^Citation30 [681 citations]
5	Karla Zadnik	56	Optimal paradigms for the contact lens correction of keratoconus; determining the relationship between ethnicity and refractive error.	Parental myopia, near work, school achievement, and children’s refractive error^Citation31 [441 citations]
6	Debra Schaumberg	55	Inflammatory/immune-mediated processes in the pathogenesis of age-related macular degeneration; dry eye pathophysiology and treatment.	Prevalence of dry eye syndrome among US women^Citation32 [804 citations]
7	Nathan Efron	55	Ocular response to contact lens wear; ophthalmic markers of diabetic neuropathy; clinical applications of corneal confocal microscopy.	Surrogate markers of small fibre damage in human diabetic neuropathy^Citation33 [357 citations]
8	William Christen	53	Neuroplasticity of vision; risk factors for cataract; impact of aspirin, vitamins and antioxidants on ophthalmic and systemic disease; epidemiology.	Vitamins E and C in the prevention of cardiovascular disease in men: The physicians’ health study II randomised controlled trial^Citation34 [610 citations]
9	Earl Smith	53	Role of vision in regulating refractive development and eye growth; aetiology of myopia; optics of the eye.	Ganglion cell losses underlying visual field defects from experimental glaucoma^Citation35 [384 citations]
10	Brien Holden	53	Ocular response to contact lens wear; epidemiology of uncorrected refractive error; arresting myopic progression with contact lenses.	Global prevalence of myopia and high myopia and temporal trends from 2000 through 2050^36 [763 citations]

Table 2 is a rank order list of the 10 most highly cited optometrists. Konrad Pesudovs heads this list, with 51,193 citations. Table 3 lists the 12 Top 200 optometrists who have achieved at least 1,000 citations in a single year. Konrad Pesudovs leads this list with 12,647 citations in 2020.

Table 2. Top 10 ranked most highly cited optometrists.

Rank	Name	Citations
1	Konrad Pesudovs	51,193
2	Janet Leasher	47,515
3	Kovin Naidoo	28,555
4	Colm McAlinden	16,783
5	Robert Hess	14,578
6	Dennis Levi	14,576
7	Gerald Westheimer	11,726
8	Debra Schaumberg	11,371
9	Nathan Efron	11,089
10	Brien Holden	10,699

Table 3. Top 200 optometrists that have been cited at least 1,000 times in a single year.

Rank	Name	Citations	Year
1	Konrad Pesudovs	12,647	2020
2	Janet Leasher	10,733	2020
3	Colm McAlinden	8049	2020
4	Kovin Naidoo	6304	2020
5	Lyndon Jones	1554	2020
6	Fiona Stapleton	1441	2020
7	Debra Schaumberg	1289	2020
8	James Wolffsohn	1234	2020
9	Nathan Efron	1115	2020
10	Jennifer Craig	1102	2020
11	Kelly Nichols	1088	2020
12	Jason Nichols	1060	2020

The top 10 ranked most prolific authors are presented in Table 4. Robert Hess (442 papers) is seen to have the highest output by a wide margin from second-ranked Nathan Efron (381 papers). Only six optometrists have published more than 300 papers.

Table 4. Top 10 ranked most prolific optometrists.

Rank	Name	Papers^a
1	Robert Hess	442
2	Nathan Efron	381
3	Brien Holden	345
4	Dennis Levi	338
5	Lyndon Jones	327
6	Konrad Pesudovs	301
7	Robert Montés-Micó	299
8	Kenneth Ciuffreda	298
9	David Atchison	285
10	Jay Enoch	285

^aTie broken according to publication rate (number of papers published per year between date of first and last recorded publication).

Table 5 identifies optometrists with the shortest year-span of publications, in each set of 10-rank increments, from ranks 1 to 100. Optometrists listed in this table could be considered as being ‘peak performers’ compared with their peers with comparable h-indices, because achieving a higher h-index in a shorter period of time is considered to be more impactful.

Table 5. Optometrists with the shortest year-span of publications, in each 10-rank increment, from ranks 1 to 100.

Ranking range	Minimum years spanning publications	Individual ranking	Name	h-index	Papers	Citations
1–10	28	1 6	Konrad Pesudovs Debra Schaumberg	67 55	301 138	51,193 11,371
11–20	24	14	Robert Montés-Micó	47	299	7454
21–30	20	21	Jason Nichols	45	156	6415
31–40	15	33	Janet Leasher	39	64	47,515
41–50	11	49	Colm McAlinden	36	119	16,783
51–60	24	51	Rebecca Ivers	36	274	5407
61–70	15	63	Mitra Tavakoli	33	65	3170
71–80	15	74	Scott Read	31	107	2751
81–90	22	87	Michael Twa	29	160	2456
91–100	11	95	Ioannis Petropoulos	28	89	2294

Table 6 list the top 10 optometrists according to rate of publication, calculated by dividing the total number of papers by the year range of publications. This parameter indicates the number of papers published by each individual per year, on average, throughout their publishing career. David Piñero has the highest output of 17.6 papers published per year.

Table 6. Top 10 optometrists ranked by publication rate.

Rank	Name	Papers	Year span of publications	Publication rate^a
1	David Piñero	282	16	17.6
2	Robert Montés-Micó	299	24	12.5
3	James Wolffsohn	264	23	11.5
4	Rebecca Ivers	274	24	11.4
5	Colm McAlinden	119	11	10.8
6	Konrad Pesudovs	301	28	10.7
7	Zhichao Wu	69	7	9.7
8	Lyndon Jones	327	34	9.6
9	José González-Méijome	206	22	9.4
10	Robert Hess	442	49	9.0

^aAverage number of papers published per year.

All 13 countries where the Top 200 optometrists work are listed in Table 7, in rank order of the h_CO-index for the Top 200 authors in each country. These h_CO-indices range from 181 (USA) to 35 (Portugal). This table reveals that a significant majority of the Top 200 (172; 86.0%) work in four nations: USA – 76 (36.0%), Australia – 43 (21.5%), UK – 41 (20.5%), and Canada – 16 (8.0%).

Table 7. Countries in which the Top 200 work, ranked according to the h_CO-index of the Top 200 affiliated with that country (for countries with three or more Top 200 optometrists).

Rank	Country	Population (million)	Number of optometry schools	Optometrists in Top 200^a	hCO- index	Total publications	Total citations	% not cited	National optometry journals
1	United States	331	23	76	181	7,785	241,471	15%	Optometry and Vision Science Journal of the American Optometric Association^a
2	Australia	26	7	43	147	5,060	174,742	13%	Clinical and Experimental Optometry
3	United Kingdom	68	12	41	119	3,676	104,847	13%	Ophthalmic and Physiological Optics Contact Lens and Anterior Eye^b
4	Canada	38	2	16	101	2,119	60,905	13%	Canadian Journal of Optometry
5	Spain	47	10	6	57	765	14,263	14%	Journal of Optometry
6	Hong Kong	8	1	6	52	553	11,805	10%	Clinical and Experimental Optometry^c
7	New Zealand	5	1	3	47	235	8259	15%	Clinical and Experimental Optometry^d
8	Portugal	10	2	3	35	220	4137	13%	Journal of Optometry^e
9	South Africa	59	4	2					African Vision and Eye Health
10	Qatar	3	0	1
11	Greece	10	1	1
12	The Netherlands	17	1	1
13	India	1366	64	1

^aSubsequently named ‘Optometry’, but discontinued in 2012

^bJournal of the British Contact Lens Association, which is a multidisciplinary association of optometrists, ophthalmologists, opticians and persons from the contact lens industry. The majority of members are optometrists.

^cAssociated via a partnership arrangement between Optometry Australia and the Hong Kong Society of Professional Optometrists.

^dAssociated via a partnership arrangement between Optometry Australia and the New Zealand Association of Optometrists.

^eAssociated via the Editor of this Spanish-based journal being Portuguese.

Table 8 lists 21 of the 72 institutions shown in the Appendix in which three or more optometrists in the Top 200 work, in rank order of h_IN-index. The h_IN-indices ranging from 132 (University of California, Berkeley) to 35 (University of Minho). The University of California, Berkeley is also home to the highest number of Top 200 optometrists (17; 8.5%).

Table 8. Institutions in which three or more of the Top 200 work, ranked according to the h_IN-index of the Top 200 affiliated with that institution.

Rank	Name	Country	Optometrists in top 200	hIN-index	Total publications	Total citations	% not cited
1	University of California, Berkeley	US	17	132	2541	87,511	15%
2	University of New South Wales	AU	14	116	2190	100,341	14%
3	Queensland University of Technology	AU	12	85	1567	39,513	11%
4	University of Houston	US	9	85	1028	34,198	18%
5	University of Waterloo	CA	12	79	1244	31,293	13%
6	Ohio State University	US	7	75	788	21,582	19%
7	University of Melbourne	AU	9	72	870	21,757	13%
8	Harvard University	US	4	71	622	22,479	11%
9	Cardiff University	UK	7	69	656	18,118	7%
10	University of Alabama at Birmingham	US	4	66	438	16,946	10%
11	Aston University	UK	6	61	661	14,651	24%
12	Marshall B Ketchum University	US	6	58	429	12,204	15%
13	University of Manchester	UK	6	57	586	15,374	9%
14	Glasgow Caldonian University	UK	3	54	365	11,035	10%
15	State University of New York	US	4	53	481	10,816	12%
16	Hong Kong Polytechnic University	HK	6	52	553	11,805	10%
17	Indiana University	US	3	50	311	9616	17%
18	University of Auckland	NZ	3	47	235	8259	16%
19	University of Illinois at Chicago	US	3	42	167	6131	10%
20	City University, London	UK	3	41	275	5816	9%
21	University of Minho	PT	3	35	220	4137	13%

Country abbreviations: AU Australia, CA Canada, UK United Kingdom, US United States of America, HK Kong Kong; NZ New Zealand; PT Portugal.

Discussion

Those included in the Top 200 can all be considered as world leaders in optometric research, by virtue of their numerous published papers of high impact in the field. They should be recognised and celebrated for their significant achievements in this regard. This listing can also be used to reflect upon the relative standing of countries and institutions in which optometric research is undertaken; however, in making such comparisons, it is important to remain cognisant of the strengths and weaknesses of publication metrics, which are discussed in detail below.

Research interests of individual optometrists

It is beyond the scope of this paper to discuss the research interests and contributions of each optometrist included in the Top 200 listing, suffice to note that, without exception, all have made remarkable contributions to the scientific foundations and knowledge-base of the profession of optometry. As can be seen from Table 1, the over-arching ophthalmic research themes among the top 10 ranked optometrists are as follows: local (ocular) and higher order (brain) neural processing of visual information (Hess, Levi, and Westheimer); contact lens, anterior eye, and refractive errors (Zadnik, Efron, Smith, and Holden); epidemiology of dry eye, cataract, and other eye diseases (Schaumberg and Christen); and ophthalmic and patient-reported outcomes (Pesudovs).

Highly cited authors

The four optometrists that head Table 2 – Konrad Pesudovs (51,193 citations), Janet Leasher (47,515), Kovin Naidoo (28,555) and Colm McAlinden (16,783) – have exceptionally high citation rates, mostly (for Pesudovs and Naidoo) and almost completely (for Leasher and McAlinden) attributable their involvement in a large multinational, interdisciplinary consortium known as the Global Burden of Disease Study. Papers from this study have been published in high impact factor journals such as Lancet, and have been cited extensively. The other six most highly cited authors have individually accrued between 10,699 and 14,578 citations.

Twelve Top 200 optometrists (Table 3) have the distinction of achieving at least 1,000 citations in a single calendar year. The number of citations accrued by Konrad Pesudovs in 2020 (12,647 citations) is greater than the entire lifetime citation count for all those listed in Table 1 except for Robert Hess and Dennis Levi (14,578 and 14,576 citations, respectively).

Prolific authors

The top 10 most prolific authors listed in Table 4 have generated a total of 3,301 papers. There is ongoing debate about the relationship between quality and quantity of published works.^2,3 However, the high h-index of all those identified as prolific authors in Table 4, and indeed among the entire Top 200 cohort, who all have h ≥ 20, provides strong evidence that their bodies of work are impactful.

Achievement in relation to years of active research

The publication metrics of the optometrists identified in Table 5 have advanced more rapidly among those of their peers with a similar rank. The median time span of publication to break into the top 100 is 36 years (the minimum is 11 years). In other words, 50% of the time it took 36 years to achieve a h-index of 28. The median time span to break into the top 50 is 37 years (minimum 11 years), requiring a h-index of 36. The median time span to break into the elite top 10 is 43 years (minimum 28 years), requiring a h-index of 53. The individuals listed in Table 4 have the shortest publishing year-span to achieve their ranking, which is considered to be an elevated level of achievement.

Publication rate

The optometrists featured in Table 6 are publishing at rate of between about nine and 18 papers per year, which approximates to one paper every three to six weeks. Two Spanish optometrists – David Piñero and Robert Montés-Micó – head this table, with publication rates of 17.6 and 12.5 papers per year, respectively. The present authors predict that those featured in Table 6 are also highly likely to rise up the Top 200 rankings at a faster pace than most others.

Location of work

Many academics are peripatetic, having worked in numerous countries and institutions around the world throughout their careers. Although it is possible to extract such information from Scopus, it was considered impractical to verify and analyse all locations where each of the Top 200 have worked and to somehow proportionately attribute citation metrics to the corresponding countries and institutions. Thus, from the perspective of country/institution, this bibliometric analysis again should be considered as a ‘snapshot in time’ of where optometrists were working on 13 January 2021, or had worked before retiring or dying.

Countries

The USA is the leading optometric nation as judged by having the highest country-specific h_CO-index (181) and the highest number of Top 200 optometrists working there (76) (Table 7). The leading position of the USA can be attributed to a number of factors: (a) the USA has by far the largest population³⁷of all nations in which optometry as a profession is well developed (i.e. aside from India); (b) the USA has the greatest number of optometry schools (23, see Table 6), aside from India²³; and (c) many USA optometry schools are housed in top-rated universities, which are research driven. As well, the USA is home to the American Academy of Optometry³⁸ – the largest research-based optometric organisation that (a) has a truly global membership; (b) hosts the biggest international optometry meeting in the world; and (c) offers the largest number of awards for clinical and research achievements in the profession.

Australia (h_CO = 147; 43 optometrists in the Top 200) is ranked second, and it is worth noting that three of the top four ranked optometrists (Pesudovs, Hess, and Westheimer) originally studied optometry in Australia. The United Kingdom (h_CO = 119; 41 optometrists in the Top 200) is third in this country listing. The high ranking of Australia and the United Kingdom also reflects a strong culture of optometric research in these nations. Canada (h_CO = 101; 16 optometrists in the Top 200) is ranked fourth, which is consistent with this nation being embedded culturally and organisationally in the broader North American optometric community.

The various historical and present-day cultural links between Hong Kong, India, New Zealand, South Africa, Australia, Canada, and the United Kingdom – all current or recent members of the Commonwealth of Nations – have perhaps also mirrored the strong professional development and consequent emergence of world-leading optometrists in the first four countries listed above. Spain and Portugal have established a solid presence in recent years as an international force in optometric research, with the listing of nine optometrists from the Iberian Peninsula.

The lead author of this paper (NE) has argued,³⁹ as have many others, that a fundamental defining feature of a research-based profession is the maintenance of a learned journal. As can be seen from Table 7, the top nine countries each have at least one optometric journal, either via an organisation in those countries being the professional publisher of the journal, or through a collaborative arrangement, as in the case of Hong Kong and New Zealand partnering with Australia. Although there is no optometry journal in Portugal, there is close alignment with the Spanish publication Journal of Optometry by virtue of the current editor of that journal, José Manuel González-Méijome, as well as two members of the editorial board, being Portuguese.

Institutions and affiliations

There are approximately 245 institutions in the world where optometry is taught.²³ The Top 200 considered here work in, or are affiliated with, 72 different optometric institutions/entities. The vast majority (182; 91%) work in university optometry schools or departments, or in ophthalmic research facilities; six (3%) work in independent institutes; six (3%) work in private consultancies, three (1.5%) work in clinics/hospitals; and three (1.5%) work in the contact lens or pharmaceutical industry.

Of the top institutions listed in Table 8, eight are in the USA, five in the UK, and three in Australia. Many of the institutions listed in Table 8 have a history that goes back a century or more.⁴⁰ The three top-ranked institutions, as defined by the institution-specific h_IN-index for Top 200 optometrists who work there, are the University of California, Berkeley (h_IN = 132; 17 optometrists from the Top 200), the University of New South Wales (h_IN = 116; 14 optometrists from the Top 200), and at equal third position, the Queensland University of Technology (h_IN = 85; 12 optometrists from the Top 200) and the University of Houston (h_IN = 85; 9 optometrists from the Top 200).

Certainly, all of the optometry schools housed in the institutions listed in Table 8 can be viewed as excellent models for nurturing the research foundations of the optometric profession, achieved by employing, or being closely associated with, world-leading optometry academics. These rankings can contribute to the reputational standing of these institutions.

Publication metrics in a broad context

To be included in the Top 200 on the census date of 13 January 2021, required a h-index of 20, as dictated by the data rankings. In his original 2005 paper introducing the h-index, Hirsch⁶ claimed that, for faculty at major research universities in the USA, a h-index of 18 might be a typical value for appointment or advancement to a full professorial position. Accordingly, inclusion in the Top 200 is a reasonable indication that a university-based optometrist is operating at the level of professor (termed ‘full professor’ in some countries), where research performance is the sole or primary consideration.

To provide further context, the most recent Nobel prize for vision-related research was awarded in 1981 to neurophysiologists David Hubel (current Scopus h-index = 66; 44,336 citations, publication span 58 years) and Torsten Wiesel (h = 60; 41,820 citations, publication span 58 years), for their discoveries concerning information processing in the visual system.

Publication metrics in relation to age

An important factor that must be considered when evaluating publication metrics is the age of a scholar (likely correlated to their year span of publishing), as a longer career simply accords greater opportunity for accruing more citations. This is readily apparent in the Top 200 listing. For example, it would be unreasonable to directly compare the publication metrics of Zhichao Wu (rank #197), who has the shortest publication range of 7 years, with that of Gerald Westheimer (#4), who has the longest publication range of 75 years. Certainly, those who attain high publication metrics more quickly should also be celebrated for their accomplishment and impact.

Hirsch⁶ offers additional guidance as to the level of excellence attached to different values of h in relation to the length of career of a researcher. He suggested that after 20 years of research, a ‘successful scientist’ would have a h-index of 20; in the Top 200 list, there are 27 optometrists who have achieved this. Further, an ‘outstanding scientist’ would have a h-index of 40 after 20 years publishing; only two optometrists – Jason Nichols (rank #21) and Kovin Naidoo (rank #33) – currently meet this criterion. Finally, a ‘truly unique’ individual would have a h-index of 60 after 20 years publishing; no optometrists meet this criterion.

It should be noted that other authors may have achieved these milestones as they surpassed h-indices of 20, 40, or 60, but this cannot be determined from the current ‘snap-shot’ of the Top 200. Nevertheless, these criteria can be considered as offering an approximate guide as to the level of excellence associated with h-index values. All those listed in Table 5 have had the greatest impact in the shortest amount of time among groups of peers with similar publication metrics at this point in time, and will likely rise the most rapidly among the rankings in the future.

Publication metrics in relation to academic prizes and awards

Having outstanding publication metrics is undoubtedly used as a key criterion for awarding research prizes in optometry. It is therefore not surprising that, as a general rule, major research awards from leading optometric organisations have been received by those with higher rankings. On the other hand, many near the top of the listing have not been recognised by awards commensurate with their high scientific impact and productivity. Within the elite group of top 10 most impactful optometrists (Table 1), five have been awarded what is arguably the most prestigious accolade of the nine awards annotated in the Appendix – the Charles F Prentice Medal, by the American Academy of Optometry.³⁸

Expanding to consider the top 20 most impactful optometrists, nine have received the Glenn A Fry Lecture Award (American Academy of Optometry) but seven have not received an award from any optometric organisation assessed as part of this analysis. Many other factors can be considered when deciding such awards. Those who paved the way during the formative years of optometric research, and have been eponymously rewarded for these efforts, include Irvin Borish, H Barry Collin, Glenn Fry, Henry Peters, and Max Schapero. None of these pioneers feature in the Top 200, largely because their seminal contributions were made prior to 1970, when citations were not counted by Scopus (see below).

Notwithstanding their generally excellent citation metrics, ‘less-published’ optometric awardees may have been honoured for more subjective, but nevertheless praiseworthy and highly valued research-related attributes, such as leadership and mentorship, the significance of which cannot be captured or measured by citation metrics alone. The following award-winning optometrists who pioneered a forward path around the beginning of the modern era of optometric research (1960s and 1970s) and appear in the lower half of the Top 200 listing are considered to be legendary figures: Thomas Freddo (#103), Robert Mandell (#111), Jan Bergmanson (#112), Joseph Barr (#113), Gunilla Haegerstrom-Portnoy (#137), Ian Bailey (#138), Michel Guillon (#144), Richard Hill (#147), Charles McMonnies (#176), Barry Weissman (#194), Elwin Marg (#195) and Merton Flom (#196).

Publication metrics in relation to specific high-impact discoveries

Some authors appear lower down the Top 200 listing due to being less prolific (thus limiting their h-index) but who have nevertheless made outstanding contributions via a single critically important discovery – an example being the development of the logMAR visual acuity chart which has revolutionised the assessment of vision in clinical research and practice. This tool was developed by Jan Lovie-Kitchin (#90) and Ian Bailey (#138). The original paper describing this chart⁴¹ has to date received 1,068 citations, which is more than the number of citations attributed to the most highly cited papers of those optometrists ranked #3 to #10 (see Table 1). The h-index does not properly reflect the excellence of those with highly skewed citation profiles (i.e. having published a small number of very highly cited papers) as in the case of Lovie-Kitchin and Bailey; as discussed earlier, other citation metrics, such as the g-index, would better reflect the excellence of such contributions.

Confounding effects in the consideration of publication metrics

There are a number of influences that can create an ‘uneven playing field’, potentially confounding a comparison of publication metrics between individuals.

Papers with hundreds of authors

An individual may publish a highly cited paper that lists hundreds of authors, which raises the issue of how much credit should be attributed to that individual. For example, if a paper with 300 authors is cited 5,000 times, it would be incongruous to credit each of these 300 authors with 5,000 individual citations.

Four optometrists – Konrad Pesudovs (rank #1), Kovin Naidoo (#33) Janet Leasher (#38), and Colm McAlinden (#49) – have published a large number of papers, each listing hundreds of authors and mostly published in the journal Lancet, relating to the Global Burden of Disease Study. The mega-author collaborations of these optometrists are evident from inspection of the ‘Co-authors’ column in the Appendix, where it can be seen that the number of career co-authors of each is as follows: Pesudovs, 4,864; Naidoo, 3,347; Leasher, 4,255; and McAlinden, 3,749. This compares with a mean (± standard deviation) of 165 ± 631 co-authors, and a median of 146 co-authors, for the Top 200.

The Global Burden of Disease Study papers have been published in high impact journals, attracting very high rates of citations; one paper²⁷ upon which Pesudovs, Naidoo, and Leasher are three of 362 authors, has accrued 5,305 citations to date. Involvement in this study is reflected in the very high number of citations attributed for these three optometrists, as can be seen from Table 2. Notwithstanding (a) the real contributions made by Pesudovs, Naidoo, Leasher, and McAlinden in respect of these works, (b) the vital ‘big questions’ that such studies are able to answer, and (c) the importance of optometrists being involved in such high-level international collaborations, being part of a large authorship team necessarily dilutes individual contributions.

Working in different disciplines

Three optometrists in the Top 200 have worked in fields outside optometry for almost their entire careers (although it also is recognised that other Top 200 optometrists have also ‘dabbled’ in fields outside of optometry). Clare Vajdic (rank #17) and Rebecca Ivers (#51) initially trained as optometrists and began research careers in vision science; however, early on, both subsequently chose to change research direction and pursue careers in the fields of cancer epidemiology and injury prevention, respectively. Lawrence DeLucas (#79) is a former NASA astronaut with degrees in chemistry, biochemistry, and optometry. He researches in the field of protein crystal growth and membrane proteins.

About one third of the Global Burden of Disease study papers co-authored by Pesudovs, Naidoo, Leasher, and McAlinden specifically relate to ophthalmic disorders and vision loss; the majority of these papers quantify the health effects of hundreds of diseases and injuries, of which ophthalmic disease is a small part. For example, the Global Burden of Disease study paper co-authored by Pesudovs, Naidoo, and Leasher referred to above²⁷ considers 291 diseases and injuries, only 6 of which relate to the eye; that is, only 2% of this paper has ophthalmic content. Involvement in the Global Burden of Disease study has served to boost the h-indices of Pesudovs and Naidoo by 20% to 25%, respectively, and to account for virtually the entire h-index of Leasher and McAlinden.

Each of the fields in which Ivers, Vajdic, and DeLucus work – as well as the subject matter of the non-ophthalmic-specific Global Burden of Disease study papers – has a far broader reach than optometry and vision science; this is an important consideration because, in general, broader fields are supported by journals that have commensurately higher citation rates and impact factors.⁴² Thus, the optometrists discussed above who wholly or substantially publish papers in broad fields unrelated to optometry and vision science have been able to attract disproportionately more citations per paper than would have been the case had they had published exclusively in the relatively smaller field of optometry and vision science.

These examples serve to illustrate the susceptibility of citation metrics to extraneous factors such as the size and reach of the discipline in which one works,⁴² and underscores the importance of comparing publication metrics of individuals in the context of the research being conducted.

Scopus not counting citations prior to 1970

The methodology used by Scopus to count citations puts the 23 optometrists in the Top 200 who commenced publishing prior to 1970 at a distinct disadvantage, in addition to many others who did not even make the list because of this issue. This is because Scopus only counts citations accrued from 1970 onwards.

Consider the example of Gerald Westheimer, who is one of the most disadvantaged in this regard. His first paper⁴³ was published in 1945, and his most recent paper to date⁴⁴ appeared in 2020. Citations of all of his papers published between 1945 and 1969 inclusive – a span of 25 years – are not counted towards his h-index or total citation count. Although citations to the pre-1970 papers of Westheimer are counted from 1970 onwards, Scopus essentially ‘ignores’ the first quarter of a century of his work, during which time others publishing prior to 1970 were citing his scholarly papers. Westheimer may well have assumed an even higher ranking had all citations to his works been counted. Accordingly, the analysis presented here should be considered as one which favours the contemporary rather than historic optometric research landscape.

A high citation rate is not necessarily a positive attribute

Caution needs to be exercised when considering citations, as a paper might be highly cited because it has made a fundamentally flawed contribution. For example, papers which have been discredited, such that of Fleischmann and Pons⁴⁵ proclaiming the viability of cold fusion (875 citations) or that of Wakefield et al.⁴⁶ suggesting that vaccinating children can cause autism (1,580 citations), are highly cited largely by those who have subsequently, and quite properly, sought to disprove these erroneous claims. The Wakefield paper⁴⁶ was later retracted by the publishing journal, Lancet. Over-enthusiastic self-citations (i.e. citing your own papers) can also distort rankings. Notwithstanding these caveats, the authors of this work are unaware of such confounding influences in respect of any of the Top 200 optometrists listed here.

Gender, racial and ethnic balance

Until about 1970, optometric research was dominated by men. However, this has changed dramatically over the past half-century, and women now figure prominently in optometric research worldwide. Indeed, Clinical and Experimental Optometry recently celebrated women research pioneers in Australian optometry in a special virtual issue of the journal.⁴⁷ The evidence for the ascendency of women in optometric research can be seen in the publication metrics presented here, whereby there are at present 61 women among the Top 200 (30.5%) and two among the elite top 10 (20%).

The gender balance of optometry graduates has become more even over the past decade; for example, in Australia in June 2020, 60% of registered optometrists were women.⁴⁸ The authors predict that this trend will eventually be reflected in an equal gender balance in optometric research worldwide, including tables of Top 200 performers such as that presented here. However, the authors note with some concern that there appears to be no present or emerging equality in racial or ethnic balance in optometric research worldwide.

Contribution to optometry of researchers from other disciplines

Only optometrists are included in this analysis. The leading optometry schools, as well as employing optometrists, recruit academics with a range of different basic qualifications and research interests to deliver important contributions to optometric education and research. This includes optical physicists, optical engineers, cell biologists, anatomists, ophthalmologists, psychologists, microbiologists, vision scientists, neurophysiologists, endocrinologists, material scientists, biostatisticians, etc. The academic strength – as assessed by the publication metrics presented here – of an optometry school that comprises a large percentage of highly published non-optometry-qualified staff may therefore be considerably under-estimated. The analysis of optometry schools in this work should therefore be considered as relating to the publication metrics of the optometrists who work there.

Including non-optometrists in this analysis was not considered viable in view of the near impossibility of deciding criteria for inclusion. Suffice to say, the authors acknowledge the critical contributions of those scientists who collaborate with optometrists to deepen the vision science knowledge base and ultimately enhance vision and ocular health in society.

Overall limitations of this analysis

Bibliometric analysis is not a perfect science. A number of limitations to the present work, and confounding influences in the consideration of publication metrics, have already been discussed. There has been no evaluation in this work of the impact of the journals in which the works are being published. For example, an individual can publish numerous papers in lower impact journals, receive numerous citations, and therefore achieve a higher h-index, perhaps with relative ease in the publication process. The alternative is that an individual could publish fewer papers in much higher impact journals (e.g., Science and Nature), which arguably represents a much higher threshold. A co-analysis of journal impact factors is outside the scope of the present work, but may be the subject of a subsequent analysis.

As discussed previously, a key reason for limiting this listing to a Top 200 was to minimise the risk of failing to discover some optometrists who have h-indices that would warrant inclusion. However, given that this listing is the product of a global search (albeit extensive), requiring manual identification of optometrists for inclusion, it is inevitable that some names will have been missed. The authors apologise unreservedly for overlooking any colleagues who should be listed in the Top 200, or for any errors in names, affiliations, countries, or the metrics presented. Any of these issues can be promptly corrected via the process explained below.

The on-line global optometrist top 200 research ranking

Many of the limitations outlined above are being mitigated by the authors of this work by way of maintaining a live version of the Global Optometrist Top 200 Research Ranking (www.optomrankings.com), that is automatically updated every 24 hours.²⁵ Interested parties are invited to submit the names of optometrists and their corresponding Scopus Author ID numbers – which are available on the Scopus website (www.scopus.com) – thought to be missing, or to suggest other edits or corrections, using links to dedicated forms which can be found in the preamble on the website. Submitted names will be uploaded to Scopus for interrogation and extraction of associated bibliometric data. Such names will be added to the data base within a few days, and will appear in the Top 200 listing if (a) the name is verified to be an optometrist, and (b) the suggested optometrist has a h-index that, after tie breaking (if required), ranks above the optometrist at rank #200. At regular intervals, the list will be manually curated by the authors to address any suggestions submitted through the web portal.

Conclusions

This bibliometric analysis demonstrates that optometry is underpinned by a robust research base, prosecuted by a large international cohort of optometric researchers who publish extensively on a broad range of ophthalmic issues and whose work is highly cited.

Although this work focusses on those optometrists who have a prolific output of impactful papers, the field of optometry is advanced by all contributions, including those by individuals who, for whatever reason, have perhaps only managed to publish a small number of papers throughout the course of their career. Accordingly, the authors of this work wish to salute and congratulate all those who have published scientific articles, no matter how few, for their dedication and commitment to the advancement of optometry and vision science.

By constructing the Global Optometrist Top 200 Research Ranking, as shown in the Appendix, the present authors have sought to identify and celebrate world leaders in optometric research. It is envisaged that the on-line web version of the Global Optometrist Top 200 Research Ranking (www.optomrankings.com)²⁵ will serve as an ongoing, visible benchmark for excellence, and will perhaps inspire and motivate subsequent generations of optometrists who seek to contribute to underpin the intellectual fabric of the profession of optometry.

Acknowledgements

The authors thank the following optometrists who provided assistance in identifying leading optometric researchers in various countries and regions around the world: Balsam Alabdulkader (Saudi Arabia), Pauline Cho (Hong Kong), Jennifer Craig (New Zealand), José Manuel González-Méijome (Portugal), Heiko Pult (Germany), Sangeetha Srinivasan and Anuradha Narayanan (India), Genis Cardona Torradeflot (Spain), and Mark Bullimore and Noel Brennan (United States). We also thank other colleagues who assisted but are not named, or declined our request to be named.

Disclosure statement

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Appendix

Global Optometrist Top 200 Research Ranking

Table

Rank	Name	Institution/affiliation	Country	h-index	Papers	Citations	Co-authors	First paper	Last paper
1	Konrad Pesudovs^a,b,i	University of New South Wales	AU	67	301	51,193	4864	1992	2020
2	Robert Hess^a	McGill University	CA	64	442	14,578	391	1971	2020
3	Dennis Levi^c,d	University of California, Berkeley	US	61	338	14,576	198	1972	2020
4	Gerald Westheimer^a,d	University of California, Berkeley	US	57	256	11,726	69	1945	2020
5	Karla Zadnik^c,d,e	Ohio State University	US	56	211	9941	343	1984	2020
6	Debra Schaumberg	Evidera	US	55	138	11,371	694	1992	2020
7	Nathan Efron^a,c,e,f,g	Queensland University of Technology	AU	55	381	11,089	342	1977	2020
8	William Christen	Harvard University	US	53	161	8897	731	1982	2020
9	Earl Smith^c,d	University of Houston	US	53	216	9466	244	1976	2020
10	Brien Holden^a,c,d,e,f,g	University of New South Wales	AU	53	345	10,699	401	1971	2019
11	Ralph Freeman^d	University of California, Berkeley	US	53	176	10,633	72	1966	2021
12	Balwantray Chauhan	Dalhousie University	CA	52	201	7947	347	1985	2021
13	Fiona Stapleton^a,c,e,f	University of New South Wales	AU	48	277	9038	473	1989	2021
14	Robert Montés-Micó	University of Alicante	ES	47	299	7454	211	1997	2021
15	Lyndon Jones^c,e,f,i	University of Waterloo	CA	47	327	8825	490	1987	2021
16	Susan Cotter^c	Marshall B Ketchum University	US	47	134	5964	880	1986	2021
17	Claire Vajdic	University of New South Wales	AU	46	171	8367	1008	1995	2020
18	Donald Mutti	Ohio State University	US	46	160	7391	360	1986	2020
19	Joanne Wood^c	Queensland University of Technology	AU	46	227	6408	259	1986	2020
20	Tailoi Chan-Ling	University of Sydney	AU	46	107	6500	361	1983	2019
21	Jason Nichols^b	University of Alabama at Birmingham	US	45	156	6415	433	2000	2020
22	Kelly Nichols^b	University of Alabama at Birmingham	US	45	113	8246	233	1999	2020
23	Ronald Harwerth^c,d	University of Houston	US	45	160	6540	136	1971	2020
24	Clifton Schor^c,d	University of California, Berkeley	US	44	200	5866	135	1969	2020
25	James Wolffsohn^i	Aston University	UK	43	264	6978	639	1998	2021
26	Michael Collins	Queensland University of Technology	AU	43	243	6092	220	1984	2021
27	David Atchison^c	Queensland University of Technology	AU	43	285	6476	1857	1979	2021
28	Algis Vingrys	University of Melbourne	AU	42	218	5648	226	1978	2021
29	Kenneth Ciuffreda^c	State University of New York	US	42	298	5994	230	1974	2021
30	David Elliott^c	University of Bradford	UK	41	171	5587	139	1987	2020
31	Trefford Simpson	University of Waterloo	CA	41	163	5247	135	1986	2020
32	Alan Tomlinson^e,f	Glasgow Caledonian University	UK	41	154	6374	269	1969	2018
33	Kovin Naidoo^g,h	African Vision Research Institute	ZA	40	128	28,555	3347	2000	2020
34	Erica Fletcher^a,b,c	University of Melbourne	AU	40	137	4532	253	1990	2020
35	Suzanne Fleiszig^b,c,e	University of California, Berkeley	US	40	115	4506	246	1983	2020
36	Anthony Adams^a,c,d	University of California, Berkeley	US	40	231	5553	118	1967	2015
37	Donald Mitchell^a	Dalhousie University	CA	40	116	4089	89	1966	2019
38	Janet Leasher	Nova Southeastern University	US	39	64	47,515	4255	2005	2020
39	Neville McBrien	University of Melbourne	AU	39	78	4646	78	1984	2017
40	Desmond Fonn^e,f,g	University of Waterloo	CA	39	172	4439	137	1982	2019
41	Eli Peli^c,d	Harvard University	US	39	272	6480	215	1979	2020
42	Michel Millodot	Cardiff University	UK	39	135	4352	128	1965	2020
43	Bernard Gilmartin	Aston University	UK	38	180	4523	113	1980	2020
44	Jack Greiner	Clinical Eye Research of Boston	US	38	138	4368	364	1976	2020
45	Raymond Applegate^c,d	University of Houston	US	38	132	5736	145	1975	2021
46	Donald Korb^e,f,g	Ocular Research Boston	US	38	101	4445	124	1968	2020
47	Christine Wildsoet^c	University of California, Berkeley	US	37	136	4870	194	1984	2020
48	Deborah Sweeney^e,f,g	Western Sydney University	AU	37	133	4416	181	1983	2019
49	Colm McAlinden	Singleton Hospital	UK	36	119	16,783	3749	2010	2021
50	David Piñero	University of Alicante	ES	36	282	4382	361	2005	2021
51	Rebecca Ivers	University of New South Wales	AU	36	274	5407	3528	1997	2021
52	Brad Fortune^b	Legacy Devers Eye Institute	US	36	115	4139	178	1994	2021
53	Mark Bullimore	University of Houston	US	36	159	6499	187	1986	2020
54	Michele Madigan	University of New South Wales	AU	36	134	3982	333	1986	2020
55	Mitchell Scheiman^c	Salus University	US	36	123	4442	655	1975	2021
56	Ruth Manny	University of Houston	US	35	111	4177	702	1979	2020
57	Brian Brown	Queensland University of Technology	AU	35	159	3458	136	1966	2015
58	Jennifer Craig	University of Auckland	NZ	34	132	4656	271	1993	2020
59	Philip Morgan^e,f	University of Manchester	UK	34	164	4101	232	1993	2020
60	Robin Chalmers	Clinical Trial Consultant	US	34	95	3957	163	1987	2021
61	John Flanagan^c	University of California, Berkeley	US	34	167	3940	399	1984	2020
62	Jacob Sivak^c,d	University of Waterloo	CA	34	207	4173	155	1973	2020
63	Mitra Tavakoli	University of Exeter	UK	33	65	3170	170	2005	2020
64	José González-Méijome^i	University of Minho	PT	33	206	3859	390	1999	2021
65	Lotfi Merabet	Harvard University	US	33	122	5575	224	1994	2020
66	Carolyn Begley	Indiana University	US	33	86	4664	267	1990	2020
67	Pauline Cho	Hong Kong Polytechnic University	HK	33	186	4062	205	1990	2021
68	David Whitaker	Cardiff University	UK	33	115	3604	104	1985	2020
69	Michael Kalloniatis	University of New South Wales	AU	32	179	3746	199	1990	2021
70	Joseph Bonanno^c	Indiana University	US	32	111	3018	149	1985	2020
71	Maurice Yap	Hong Kong Polytechnic University	HK	32	120	2720	564	1984	2020
72	David Henson	University of Manchester	UK	32	104	4863	144	1978	2018
73	Scott Read	Queensland University of Technology	AU	31	107	2751	129	2005	2020
74	Bang Bui	University of Melbourne	AU	31	125	2666	232	1997	2021
75	Padmaja Sankaridurg^i	Brien Holden Vision Institute	AU	31	107	3352	222	1993	2020
76	Geoffrey Henry^c	Australian National University	AU	31	62	3339	36	1968	2001
77	Noel Brennan^e	Johnson & Johnson Vision	US	31	118	3110	133	1982	2020
78	Leo Carney^e,f	Queensland University of Technology	AU	31	137	3245	84	1970	2014
79	Lawrence DeLucas	University of Alabama at Birmingham	US	31	155	3332	451	1974	2019
80	Sheila Crewther	LaTrobe University	AU	31	220	3086	216	1975	2021
81	Kenneth Polse^e,f,g	University of California, Berkeley	US	31	136	2976	123	1967	2019
82	Mathew Alpern^d	University of Michigan	US	31	122	2629	97	1942	1998
83	Jay Enoch^c,d	University of California, Berkeley	US	31	285	3327	179	1951	2012
84	Nicola Pritchard	Queensland University of Technology	AU	30	76	2659	106	1992	2020
85	David Goss	Indiana University	US	30	115	2132	63	1979	2015
86	James Sheedy	Pacific University	US	30	85	2281	106	1975	2016
87	Michael Twa	University of Houston	US	29	160	2456	170	1998	2020
88	Jeremy Guggenheim	Cardiff University	UK	29	117	2734	730	1991	2020
89	Susana Chung^b,c	University of California, Berkeley	US	29	118	2785	85	1989	2020
90	Jan Lovie-Kitchin	Queensland University of Technology	AU	29	97	2666	67	1981	2015
91	Daphne McCulloch	University of Waterloo	CA	29	93	3710	154	1984	2020
92	Eric Papas	University of New South Wales	AU	29	120	3198	186	1984	2020
93	Barbara Pierscionek	Nottingham Trent University	UK	29	170	2762	237	1983	2020
94	John Wild	Cardiff University	UK	29	94	2584	126	1980	2020
95	Ioannis Petropoulos	Weill Cornell Medicine – Qatar	QA	28	89	2294	309	2010	2021
96	Lisa Keay	University of New South Wales	AU	28	183	3496	331	1998	2021
97	Nancy McNamara^b	University of California, Berkeley	US	28	80	3404	268	1994	2020
98	Paul McGraw	Glasgow Caledonian University	UK	28	116	2520	109	1993	2020
99	Bruce Evans	City, University of London	UK	28	101	2127	133	1990	2020
100	Michael Rouse	Marshall B Ketchum University	US	28	64	2387	175	1980	2013
101	Mark Rosenfield	State University of New York	US	28	100	2392	73	1986	2021
102	Carol Westall	University of Toronto	CA	28	105	2519	227	1981	2020
103	Thomas Freddo^c	University of Waterloo	US	28	83	2085	182	1976	2020
104	Teresa Ferrer-Blasco	University of Valencia	ES	27	145	2638	88	2000	2019
105	Paul Artes	Plymouth University	UK	27	61	2443	146	1999	2020
106	Allison McKendrick	University of Melbourne	AU	27	141	2370	160	1995	2021
107	Marjean Kulp	Ohio State University	US	27	80	2373	589	1994	2021
108	Li-Fang Hung	University of Houston	US	27	59	3096	48	1988	2020
109	Russell Woods	Harvard University	US	27	106	2206	129	1987	2020
110	Sudi Patel	Glasgow Caledonian University	UK	27	97	2202	124	1981	2020
111	Robert Mandell^e	University of California, Berkeley	US	27	78	1969	45	1959	2000
112	Jan Bergmanson^e,f	University of Houston	US	27	118	1924	128	1977	2019
113	Joseph Barr^e	Ohio State University	US	27	90	2498	176	1977	2020
114	Loretta Szczotka-Flynn	Case Western University	US	26	108	2355	655	1992	2021
115	Katrina Schmid	Queensland University of Technology	AU	26	111	2756	181	1991	2021
116	Timothy McMahon	University of Illinois at Chicago	US	26	73	2394	256	1981	2016
117	Steve Anderson	Aston University	UK	26	67	2149	69	1985	2020
118	Graeme Young	Visioncare Research Limited	UK	26	69	1743	83	1984	2019
119	Richard Abadi	University of Manchester	UK	26	74	1922	40	1973	2014
120	Frank Thorn	Massachusetts Institute of Technology	US	26	72	2448	202	1970	2020
121	Theodore Grosvenor	Pacific University	US	26	82	1834	42	1957	2007
122	César Villa-Collar	European University of Madrid	ES	25	96	1596	238	2003	2021
123	Katie Edwards	Queensland University of Technology	AU	25	72	2180	103	2001	2020
124	Paul Murphy	University of Waterloo	CA	25	75	2096	83	1996	2020
125	Jeffrey Walline^e	Ohio State University	US	25	57	1815	146	1996	2020
126	Chi Ho To	Hong Kong Polytechnic University	HK	25	104	1688	232	1996	2020
127	Shaban Demirel	Legacy Devers Eye Institute	US	25	87	1689	310	1994	2021
128	Kathryn Saunders	Ulster University	UK	25	98	1761	129	1992	2020
129	John Lawrenson	City, University of London	UK	25	116	2277	163	1990	2020
130	William Ridder	Marshall B Ketchum University	US	25	61	1433	96	1988	2019
131	Dorothy Thompson	University College London	UK	25	99	1927	1519	1987	2020
132	Arthur Ho	University of New South Wales	AU	25	124	2213	152	1986	2021
133	Barry Winn	Bradford University	UK	25	54	1800	39	1981	2017
134	Ian Murray	University of Manchester	UK	25	105	2338	95	1983	2020
135	Rachel North	Cardiff University	UK	25	70	1891	108	1979	2020
136	Neville Drasdo	Cardiff University	UK	25	81	2053	58	1965	2010
137	Gunilla Haegerstrom-Portnoy^e	University of California, Berkeley	US	25	76	1962	61	1975	2020
138	Ian Bailey^c,d	University of California, Berkeley	US	25	96	7925	135	1970	2017
139	Sarah Hosking	Australian College of Optometry	AU	24	65	1545	78	1996	2015
140	Timothy Edrington	Marshall B Ketchum University	US	24	56	2125	223	1989	2018
141	Daniel O’Leary	Anglia Ruskin University	UK	24	58	1755	66	1979	2013
142	Barbara Caffery	Kensington Vision Research Centre	CA	24	123	4295	159	1980	2019
143	Richard Van Sluyters	University of California, Berkeley	US	24	53	2517	33	1972	2012
144	Michel Guillon^e,f	Ocular Technology Group	UK	24	103	1779	98	1979	2020
145	Gordon Ruskell	City, University of London	UK	24	62	1525	28	1960	2005
146	Margaret Woodhouse	Cardiff University	UK	24	71	1522	106	1975	2020
147	Richard Hill^c,d,e,f	Ohio State University	US	24	280	3620	103	1962	2012
148	Lauren Ayton	University of Melbourne	AU	23	51	1278	125	2009	2021
149	Stacey Choi	Ohio State University	US	23	63	2102	104	2003	2019
150	Michael Crossland	University College London	UK	23	57	1506	152	2002	2020
151	Hema Radhakrishnan	University of Manchester	UK	23	81	1552	75	2002	2021
152	Alejandro Cerviño	University of Valencia	ES	23	90	1699	108	2000	2020
153	Charlotte Joslin	University of Illinois at Chicago	US	23	62	2997	457	2000	2021
154	Marion Edwards	Hong Kong Polytechnic University	HK	23	53	1866	43	1989	2012
155	Jorge Jorge	University of Minho	PT	23	56	1364	54	1997	2020
156	Carly Lam	Hong Kong Polytechnic University	HK	23	54	1779	148	1991	2020
157	Andrew Lam	Hong Kong Polytechnic University	HK	23	94	1786	134	1991	2021
158	Craig Woods	University of New South Wales	AU	23	92	1435	138	1989	2020
159	Robert Harper	University of Manchester	UK	23	76	1556	168	1988	2020
160	Shahina Pardhan	Anglia Ruskin University	UK	23	126	1606	169	1987	2021
161	Philip Kruger	State University of New York	US	23	49	1362	55	1975	2019
162	Jeffrey Cooper	State University of New York	US	23	73	1927	301	1974	2021
163	William Harris	University of Johannesburg	ZA	23	167	1854	33	1970	2019
164	Nicole Carnt	University of New South Wales	AU	22	67	1345	204	2002	2020
165	Clare O’Donnell	Optegra	UK	22	48	1384	46	1998	2018
166	Harrison Weisinger	University of Western Australia	AU	22	53	1764	80	1995	2016
167	Sotiris Plainis	University of Crete	GR	22	62	1224	107	1998	2019
168	Vijaya Gothwal	LV Prasad Eye Institute	IN	22	84	1595	99	1997	2020
169	Shehzad Naroo	Aston University	UK	22	132	1557	199	1996	2020
170	Christopher Hudson	University of Waterloo	CA	22	78	1435	174	1992	2019
171	Wendy Marsch-Tootle	University of Alabama at Birmingham	US	22	54	2064	609	1989	2020
172	Leon Garner	University of Auckland	NZ	22	64	1246	45	1972	2006
173	Luigina Sorbara	University of Waterloo	CA	22	79	1428	91	1982	2021
174	Helen Swarbrick	University of New South Wales	AU	22	74	2151	102	1979	2020
175	William Bobier	University of Waterloo	CA	22	78	1541	104	1977	2020
176	Charles McMonnies^f	University of New South Wales	AU	22	135	2066	46	1966	2021
177	Barry Cole	University of Melbourne	AU	22	135	1507	48	1962	2020
178	Korine van Dijk	Institute for Innovative Ocular Surgery	NL	21	52	1612	69	2011	2020
179	David Madrid-Costa	Complutense University of Madrid	ES	21	94	1270	92	2008	2020
180	Caroline Blackie	Johnson & Johnson Vision	US	21	42	1580	61	2005	2018
181	António Queirós	University of Minho	PT	21	60	1115	65	2004	2020
182	Ed Mallen	University of Bradford	UK	21	64	1569	74	2000	2020
183	Alex Gentle	Deakin University	AU	21	28	1831	37	1997	2020
184	Paul Spry	Bristol Hospital Eye Service	UK	21	50	1669	120	1995	2020
185	Frank Eperjesi	Aston University	UK	21	72	1474	86	1995	2020
186	Ian Cox	University of Rochester	US	21	46	1938	63	1989	2017
187	Andrew Metha	University of Melbourne	AU	21	59	1773	97	1992	2020
188	Eric Borsting	Marshall B Ketchum University	US	21	42	1777	272	1991	2021
189	Daniel Twelker	University of Arizona	US	21	42	1900	108	1988	2020
190	Elise Ciner	Salus University	US	21	47	1229	186	1986	2019
191	Joan Stelmack	University of Illinois at Chicago	US	21	46	1351	110	1987	2021
192	John Phillips	University of Auckland	NZ	21	40	2397	35	1981	2020
193	Anthony Cullen	University of Waterloo	CA	21	72	1703	105	1969	2012
194	Barry Weissman^e,f	Marshall B Ketchum University	US	21	137	1739	271	1973	2020
195	Elwin Marg^c,d	University of California, Berkeley	US	21	87	1686	77	1949	1997
196	Merton Flom^d	University of Houston	US	21	81	1758	67	1955	2009
197	Zhichao Wu	University of Melbourne	AU	20	69	1110	143	2013	2020
198	Stephen Vincent	Queensland University of Technology	AU	20	101	1292	113	2009	2021
199	Lakshman Subbaraman	University of Waterloo	CA	20	70	1238	131	2005	2020
200	Leon Davies	Aston University	UK	20	55	1370	71	2003	2020

Country abbreviations: AU Australia, CA Canada, ES Spain, GR Greece, HK Hong Kong, IN India, NL The Netherlands, NZ New Zealand, PT Portugal, QA Qatar, UK United Kingdom, US United States of America, ZA South Africa.

Major optometry awards: a. H Barry Collin Medal (Optometry Australia); b. Irvin M and Beatrice Borish Award (American Academy of Optometry); c. Glenn A Fry Lecture Award (American Academy of Optometry); d. Charles F Prentice Medal (American Academy of Optometry); e. Max Schapero Memorial Lecture Award (American Academy of Optometry); f. BCLA Medal (British Contact Lens Association); g. Ruben Medal (International Society for Contact Lens Research); h. Henry B Peters Memorial Award in Public Health and Environmental Vision (American Academy of Optometry); i. International Optometrist of the Year Award (Polytechnic University of Catalonia [Spain]).