Addressing common myths and misconceptions in soft contact lens practice

ABSTRACT

Advances in contact lens technology over the past 50 years since the commercialisation of the first soft lenses in 1971 have been incredible, with significant changes in contact lens materials, frequency of replacement, care systems and lens designs occurring. However, despite the widespread availability of contact lenses, penetration rates for those who need vision correction remain in the low single digits and many practitioners seem to hold on to concepts around the potential value of contact lenses that appear based in the dim and distant past and are certainly no longer valid today. This review addresses 10 common ‘myths and misconceptions’ around soft contact lenses using an evidence-based approach that can hopefully dispel some of these incorrect assumptions.

KEYWORDS:

• Clinical practice
• misconceptions
• myths
• soft contact lenses

Introduction

In the wider area of general health care it has been stated that it takes an average of 17 years for clinical research to reach clinical practice, with many steps recognised as being involved in that process, including basic and human research, development of guidelines and adoption in practice.¹ Behaviour change in routine health care is notoriously difficult to achieve, and it has been suggested that about 30–40% of patients do not receive care according to current scientific evidence.² Narrowing the focus to soft contact lens (CL) practice whilst bearing this knowledge in mind raises questions in relation to commonly held beliefs among eye care practitioners and how well contemporary evidence-based clinical practice is adopted. Given the pace at which CL material and care system technology evolves, along with ever-improving understanding of their impact on ocular physiology, it is possible that historical views continue to exist that are no longer a cause for concern based on current evidence.

The relatively fast pace of change in technology and knowledge in comparison to slower-changing practitioner and consumer beliefs was addressed by Efron and colleagues^3,4 in two publications that examined the myths and realities of CL fitting and wear. Three decades on from those reviews, it seems prudent to examine some current popular beliefs in relation to soft CL fitting. Grouped into three broad topic areas related to the CL and care system, patient-related concerns and business-focused barriers, this review examines the evidence to support or debunk 10 commonly held beliefs. Given the 30-year timespan since Efron and co-workers^3,4 first tackled this issue, it is perhaps remarkable to recognise that six of the topics addressed in this review were also covered in those original papers. While technology and clinical understanding have no doubt changed considerably over time, it appears some inertia remains in shaking off historical, and now outdated, views on CL success, suitability and profitability.

Contact lens and care system

Increasing oxygen transmissibility improves lens comfort

While not specifically addressed in the initial ‘myths’ publications by Efron and colleagues,^3,4 broad consideration of methods to enhance on-eye comfort of lenses has been of significant interest for practitioners and manufacturers alike for decades.

The concept around enhancing comfort through increased oxygen dates back to the late 1970s, with the advent of gas-permeable rigid corneal lenses, which provided improved comfort over the PMMA lenses available at that time.⁵ The introduction of soft lenses and their improved speed of patient adaptation and comfort over rigid lenses led to their rapid adoption.⁶ The next time this concept of increased oxygen resulting in improved comfort gained traction during the commercialisation of silicone hydrogel (SiHy) materials in the late 1990s. The introduction of SiHy lenses certainly eliminated many of the previous hypoxic complications seen with hydrogel lenses, particularly in those patients with thick lens designs in which the oxygen transmissibility was markedly reduced or when lenses were worn overnight.^7–13

In addition to longer wearing times being reported,¹⁴ some initial studies did indeed report increased comfort and reduced reports of dryness in patients refit from hydrogels into SiHy materials.^15–19 An early review suggested that increased oxygen permeability was associated with greater lens comfort,⁸ a view supported in a more recent review.²⁰ In these early studies, where hydrogel wearers were simply refit into SiHy materials, study designs were not ideal, with little or no masking, randomisation, use of concurrent controls or systematic variations in design or manufacturing method.^21,22 These issues could have potentially resulted in erroneous conclusions concerning the potential benefits of the newer materials regarding on-eye comfort. It is interesting to note that CL wearers can be broadly divided into those who are either symptomatic or asymptomatic, and that comfort drops off across the day more quickly for the symptomatic group.²³ When previous hydrogel wearers were refit into SiHy materials this drop-off in comfort still occurred across the day,¹⁴ and it is possible that these early studies may have been influenced by the study design or subjects enrolled.

Studies investigating reusable SiHy materials were unable to demonstrate any significant comfort benefits for SiHy materials compared to hydrogels,^24,25 with more recent studies arriving at the same conclusion for daily disposable materials.^26,27 Four evidence-based reviews have concluded that there is no overall comfort benefit obtained by merely increasing oxygen transport through the lens.^21,22,28,29 While some wearers will indeed find improved comfort by switching to a modern SiHy material, the differences in lens design, edge form, frictional forces, surface chemistry, manufacturing method, modulus, potential interaction with any associated care system or tear film components, etc., make it impossible to definitively confirm that this comfort improvement is linked to oxygen transport alone.

Hydrogels should no longer be fitted

Silicone hydrogel materials represent almost three-quarters (73%) of all soft lenses fit across a variety of countries around the globe, accounting for 80% of reusable lenses and 63% of daily disposable lenses.³⁰ This is interesting, given that SiHy materials have been commercially available for over 20 years, and that it would seem conceivable that the increased oxygen afforded to the cornea by them should have made them the first choice of lens for all patients. So, why after 20 years do hydrogel lenses still account for almost 25% of all new fits? It is clear that some practitioners continue to prescribe hydrogel lenses (that are often made from materials developed in the 1980s or even earlier), new hydrogel lenses are still being launched in the market and existing wearers continue to wear them successfully.

The essential differences between hydrogel and SiHy materials relate to the incorporation of siloxane components, which significantly increase the oxygen permeability (Dk) of the lens materials.^31–33 As previously described, this has certainly eliminated the hypoxic complications seen with thick hydrogels, especially those worn overnight.^7–13 Thus, should all patients be fit with SiHy materials given this information? A recent review of arguably the hydrogel material that is most commonly prescribed demonstrates that many wearers, especially those wearing lenses on a daily wear basis, show no signs of hypoxic compromise when wearing hydrogels over many years.²⁹

Calculations of the average amount of oxygen required to prevent oedema for daily wear would suggest that several hydrogel materials provide adequate oxygen to maintain healthy wear.³⁴ Short-term corneal swelling studies by Moezzi and colleagues were unable to demonstrate any difference in topographical corneal swelling between a hydrogel lens and no lens wear³⁵ and no clinically significant differences in corneal swelling when habitual, reusable, SiHy daily wear subjects were refitted into etafilcon A, multifocal, daily disposable lenses and followed for 4 weeks.³⁶

Similarly, Szczotka-Flynn and colleagues demonstrated the equivalence of etafilcon A with respect to two SiHy lenses for three measures of hypoxic stress.³⁷ A recent 6-year prospective study of children wearing daily disposable hydrogel lenses demonstrated no hypoxic complications.³⁸ Thus, while SiHy materials are beneficial for overnight wear, in patients who regularly nap in their lenses and in patients with high prescriptions or thick lens designs (as seen with toric lenses), the majority of patients appear oedema-free with hydrogels worn on a daily wear basis.

While integration of siloxane monomers provides benefits in terms of oxygen transport, a downside of their incorporation is that the modulus (or stiffness) of the material increases.^33,39–41 This provides some benefits in terms of lens handling for patients as the stiffer lenses are often easier to handle. On the other hand, it can cause some issues with fitting, with the stiffer lenses not draping over the cornea as easily as lower modulus materials, resulting in reduced initial comfort⁴² and in some cases edge stand-off or ‘fluting’,^43–45 complications that were seen more commonly with early SiHy materials. This increased modulus has resulted in reports of a number of mechanical complications with SiHy materials, including post-lens debris (mucin balls), superior epithelial arcuate lesions, corneal erosions, CL-induced papillary conjunctivitis, conjunctival epithelial flaps and lid wiper epitheliopathy (LWE).^11,45–47

Important complications with CL materials are broadly of two types: microbial keratitis (MK) and corneal infiltrative events (CIEs). Studies have shown that MK is not linked to oxygen transport and that MK is not reduced in patients wearing SiHy materials.^29,48 Similarly, CIEs have not diminished with the use of SiHy materials, and in fact the overall incidence of CIEs is higher during reusable daily and extended wear with SiHy lenses.^49,50 Several studies have demonstrated that the daily wear use of reusable SiHy lenses approximately doubles the risk of CIEs.^51–54 Hydrogel lenses may therefore be preferred over SiHy lenses in people who have experienced previous inflammatory events as CIEs are known to recur in some predisposed individuals.⁵⁵

Solution interactions with preserved care systems and SiHy lenses can occur to a greater degree than that seen with hydrogel lenses.^{29,50,56–59} The reasons for this (and the clinical relevance) remain under discussion, but it may relate to the differences in uptake and release of care system components between hydrogel and SiHy materials.^60–62

In conclusion, although improved corneal physiology from decreased hypoxia with SiHy lenses is recognised, the literature supports that, for low to moderate degrees of ametropia, daily wear hydrogel lenses do not significantly impact corneal physiology compared to SiHy lenses. This, coupled with the reduced inflammatory responses observed when used with solutions, no impact on MK or comfort, reduced mechanical complications and lower cost, means that hydrogel lenses remain an important option in modern CL practice.

Patients will be more successful wearing CL materials that demonstrate low levels of deposition

The initial ‘Myths & Misconceptions’ papers by Efron and colleagues^3,4 were published just as the concept of frequent replacement of soft lenses was becoming widely adopted, and a few years before the introduction of daily disposable lenses in the mid-1990s. While not specifically addressed in those papers, the concept of fewer complications with low-depositing materials would appear to be intuitively obvious.

Early reviews of CL deposition prior to the widespread adoption of disposability demonstrated that some patients visibly deposited their lenses.^63–65 The switch to frequent replacement certainly resulted in a reduction of clinically visible deposits,⁶⁶ but a number of analytical studies demonstrated that there was little to no correlation between visible deposits and the amount of tear film components actually deposited on lenses. Some apparently ‘clean’ lenses exhibiting substantial quantities of protein, in particular lysozyme.^66–68

There is substantial evidence that inflammatory complications such as CIEs and CL-associated papillary conjunctivitis are indeed reduced with frequent replacement lenses, particularly with lenses that are replaced on a daily disposable basis.^{29,49,50,53,69–71} Thus, the concept that practitioners should fit lenses that have minimal deposition likely relates to these findings. However, given the poor correlation between visible and analytically derived deposition quantities, how true is this? To examine this, the differences in deposition that exist between soft lens material types first need to be understood.

CL material interaction with tear film components differs markedly between materials. Relevant material factors that impact deposition include material composition, water content, pore size, surface roughness, material hydrophobicity and surface charge.^{29,33,66,72–76} Hydrogel materials tend to deposit protein to a greater extent than lipid, with the reverse true for SiHy materials.^29,76 However, within this broad concept, many subtleties exist between materials and the various proteins and lipids of the tear film. Interested readers are referred to extensive reviews on this topic.^{29,33,66,72–76}

Ionic (negatively charged) hydrogel materials uptake substantial quantities of the positively charged tear film protein lysozyme, with initial deposition occurring within minutes of the lens being placed on the eye.^77–80 After 2 weeks of wear, an etafilcon A lens will deposit several orders of magnitude more lysozyme than a surface-coated SiHy material.^29,72,81,82 A recent review has shown that etafilcon A is a very successful material and that despite this substantial deposition of a tear-film derived protein the material is associated with very low levels of inflammatory responses and maintains good comfort compared with other lenses that show much lower levels of deposition.²⁹

An extensive review demonstrated that the amount of deposited protein is unrelated to CL comfort and performance,²² and one report has linked CL comfort with the degree of denaturation of lysozyme, whereby higher amounts of denaturation were linked to lower comfort scores.⁸³ An in vitro study demonstrated that a reduction in metabolic activity and an increase in the release of inflammatory cytokines occurred after human corneal epithelial cells were exposed to denatured lysozyme.⁸⁴ Several studies have shown that FDA group IV materials such as etafilcon A have the greatest ability to conserve protein configuration and keep denatured lysozyme to low levels,^82,85–87 which could help to explain this lack of correlation between high levels of protein deposition and poor comfort.

In addition to protein deposition, many publications have examined the interaction between tear film lipids and CL materials.^{22,73,75,76,88–95} A recent paper demonstrated that an asymptomatic group of lens wearers actually deposited a significantly greater amount of lipid on their CL than a symptomatic group, suggesting that low levels of deposition of certain tear film lipids may actually improve comfort.⁹⁵

In conclusion, given the lack of evidence to show that increased amounts of deposition result in reduced comfort with the reduced wearing life of contemporary lenses, there is no evidence that fitting lenses that deposit low amounts of tear film components will result in increased comfort.

When a patient reports discomfort, the first – and most appropriate – option is to change the lens

One concern raised in the original paper of Efron and colleagues⁴ was the ‘considerable difficulty’ patients experienced in adapting to their lenses. Back in 1992, reassurance was given regarding improved polymer technology and manufacturing techniques that resulted in thin lenses with contoured edges, making adaptation to contemporary lenses of the time ‘almost instantaneous’.⁴

Dryness and discomfort are often cited as the main reasons for dropout in established wearers,^96,97 with suboptimal vision and handling concerns also associated with dropout of newly fit patients.^98,99 The report on Contact Lens Discomfort (CLD) by the Tear Film and Ocular Surface Society (TFOS) identified several CL-related factors that are associated with improved comfort, including ensuring the lens fits well, increasing replacement frequency and using materials that have good on-eye wettability and low surface friction.²² This means, when discomfort is reported, changing the soft CL to address one or more of these identified factors is a perfectly reasonable option. However, it is not the only option, and, depending on the perceived cause of the discomfort, may not be the first, or indeed best, course of action to take.¹⁰⁰

CL discomfort is multifactorial,¹⁰¹ and there are many other modifiable factors that have been identified outside of the CL itself. One of those relates to the care system used with reusable CLs. Solution-induced corneal staining (SICS) can occur with the combination of certain SiHy materials and multipurpose solutions (MPS).⁵⁹ Although equivocal data exist on whether the presence of this transitory staining impacts comfort,^56–59,102 it has been demonstrated that comfort scores differ across various combinations of SiHy material and care system.¹⁰² For patients with sensitivities to the preservatives in MPS, use of a preservative-free hydrogen peroxide (H₂O₂) system may be beneficial, both in terms of reduced corneal staining and improved comfort.^{58,59,102,103} These results demonstrate that CL comfort can be influenced by changing to an alternative care system whilst staying in the same lens. It is worth noting that when a change in frequency of replacement is feasible, refitting with daily disposables can also improve comfort, with removal of the care system resulting in better subjective comfort in a study by Lazon de la Jara and colleagues.¹⁰²

The condition of both the ocular surface and tear film influences CLD. CL wear is known to reduce the lipid layer thickness of the pre-lens tear film,¹⁰⁴ increase tear film evaporation¹⁰⁵ and reduce break-up time¹⁰⁶; changes that are thought to be associated with CLD.¹⁰⁷ In addition to discomfort that occurs during lens wear, it also possible for either ocular surface changes or dry eye disease (DED) to be present in CL wearers.¹⁰⁸ The most common type of DED is evaporative dry eye, found to occur in 86% of dry eye patients in one clinical study,¹⁰⁹ and results from a compromised or reduced tear film lipid layer.¹¹⁰ Given that CL wear also impacts the lipid layer and tear film stability, it becomes important to thoroughly check the tear film quality and quantity, lid margin health and ocular surface condition of all CL wearers during both fit and follow-up appointments.¹¹¹

Siddireddy and colleagues investigated the association between the eyelids and CLD in 30 subjects.¹¹² The CLDEQ-8 scores of symptomatic CL wearers were correlated with elevated superior LWE, eyelid margin sensitivity, lid parallel conjunctival folds, tear evaporation rate (with and without lens wear), palpebral roughness and poorer meibum quality and expressibility.¹¹² A proactive approach to dealing with mild and asymptomatic meibomian gland dysfunction (MGD) in CL wearers was recommended in the Contact Lens Evidence-Based Academic Report on CL complications.⁵⁰

There is growing evidence for managing symptomatic CL wearers with treatments designed to improve lid margin health and tear film quality.¹⁰⁰ Comfortable CL wear time was increased by an average of 1.8 h, and the number of blocked meibomian glands was significantly reduced after 4-week use of either once or twice-daily hot compresses (Bruder mask, Bruder Healthcare company, LLC, US).¹¹³ Daily use of a warm compress for 30 min in CL wearers experiencing dry eye symptoms significantly reduced Ocular Surface Disease Index (OSDI) symptom score after 4 weeks.¹¹⁴ One week after a single microblepharon exfoliation treatment (BlephEx, BlephEx LLC, US) symptomatic CL wearers exhibited improved tear film quality, improved signs of blepharitis and MGD and reduced lid margin bacterial load.^115,116

Use of in-office thermal pulsation has been explored in CL wearers. Three months after a single treatment, symptomatic soft CL wearers with signs of MGD and evaporative dry eye exhibited significantly improved symptoms and signs, reported reduced use of artificial tears and a significant improvement of an average of 4 h a day in comfortable wear time.¹¹⁷ Use of lipid-containing eye drops pre- and post-wear for 2 weeks significantly improved comfort scores using the CLDEQ-8 questionnaire in symptomatic lens wearers.¹¹⁸

LWE is thought to occur in the presence of increased friction between the lid wiper region of the lid and the anterior surface of the eye or CL.¹¹⁹ A correlation between improved CL comfort scores and lower coefficient of friction of the CL material has been reported,¹²⁰ resulting in the premise that using CLs with lower surface friction may be beneficial when LWE is found. However, a link between LWE and CLD has yet to be fully proven, with conflicting study results reported.^119,121,122 In CL wearers, use of lipid-containing artificial tears improved subjective comfort, comfortable wearing time, corneal staining and LWE grade after 1 month of use in symptomatic CL wearers.¹²³

Finally, vision quality should not be overlooked. An association between clarity of vision and ocular comfort in non-CL wearers has been reported,¹²⁴ and greater ocular comfort scores were associated with higher subjective vision quality in subjects corrected with soft toric CLs.¹²⁵

Contemporary thinking about how to address CLD continues to evolve over time. While there are often good reasons to change CL material or modality to help improve comfort, it is important to bear in mind the many other approaches that can also improve comfort (summarised in Table 1). Defaulting to always considering a change of lens when CLD manifests is not necessary, and for some situations may not represent best evidence-based practice. It is possible to improve CL comfort by ensuring the refraction is optimally corrected, by changing the care system or through addressing the health of the lid margins, meibomian glands and tear film. Given the complex and multifactorial nature of CLD, it may be appropriate to apply more than one management strategy, for example, treating MGD and refitting from a reusable to a daily disposable modality.

Table 1. Factors to consider outside of changing the contact lens when trying to improve suboptimal comfort; presented in the order they may likely be encountered in the ocular examination.

Factor	Evidence	Action
Vision	Association reported between visual clarity and ocular comfort^Citation124	Ensure CL prescription or CL optical design is optimised (e.g. toric, multifocal)^Citation125
Meibomian gland function	A proactive approach to dealing with mild and asymptomatic MGD in CL wearers has been recommended^Citation50	If signs of MGD or lid margin inflammation are noted, the use of warm compresses,^Citation113 in-office microexfoliation,^Citation115,Citation116 in-office thermal pulsation^Citation117 and lipid-containing drops^Citation118 may all help to improve CL comfort
Lid wiper epitheliopathy (LWE)	Although an association between LWE and CL discomfort has not been proven, this clinical sign is thought to occur due to increased friction between the lid wiper and anterior ocular surface (or CL)^Citation119	Use of lipid-containing drops improved signs and symptoms in one study^Citation123
Solution-induced corneal staining (SICS)	Equivocal evidence exists for an association between SICs and CL discomfort, but comfort scores do change with different combinations of material and MPS^Citation102	Consider changing the material–solution combination, switching to a preservative-free hydrogen peroxide system^Citation103 or removing the care system (necessitating a lens change) to refit with daily disposable

Patient-related concerns

Young children are less successful with contact lenses

While other patient groups such as astigmats and presbyopes were referred to in the original myth-busting papers of Efron and colleages,^3,4 the fitting of children with CLs was a notable exception. This is understandable, given the focus at the time was on addressing barriers to CL fitting in the general population. The question, three decades on, is what does the evidence say about how well children cope with CL, and is that reflected in current fitting practices? In addition to the general benefits of CL wear in children, the relevance of this topic has arguably increased over time due to the well-publicised anticipated increase in global myopia prevalence by 2050,¹²⁶ and the increasing availability of evidence-based options for myopia management, which include both soft^127–129 and orthokeratology^130–132 CL designs.

There are a number of aspects to consider when assessing the suitability of CLs for young children.¹³³ These range from the benefits they deliver, their ability to be fit successfully with a reasonable amount of chair time in practice and their relative safety in this age group.^133,134 Active children can find spectacles inconvenient during physical activities,¹³⁵ and when compared to spectacles over a 3-year period, young myopes fit with soft CLs experienced improved perception of physical appearance, athletic competence, social acceptance¹³⁶ and vision-related quality of life.¹³⁵ Teenagers fit with daily disposable CLs had improved quality of life after 1 month, with significantly increased scores compared to a spectacle-wearing group for appearance, activities, peer perception and overall score.¹³⁷ Vision-related quality-of-life benefits have also been reported in children aged 6–12 after both 1 and 2 years use of orthokeratology for myopia control.¹³⁸

The time taken to fit young children with CL has been voiced as a barrier in the past. Studies investigating this aspect of fitting have either found a small increase in time required for application and removing training of around 15 min for younger age groups (age 8–11 years), compared to teenagers (13–17 years),¹³⁹ or no significant difference between age groups, with a small proportion (5.3%) requiring a second training visit.¹⁴⁰ Children as young as 8 can successfully wear and independently care for their CLs,¹⁴⁰ a result echoed for those aged 8–12 years in a 3-year randomised controlled trial comparing a control CL to a myopia-management design where after just 1 month of wear more than 90% reported CL removal, as ‘kind of easy’ or ‘really easy’.¹²⁷

In terms of CL safety, typically the focus falls on two groups of complications: those that are inflammatory in nature (CIEs) and those that are infective, and potential sight threatening (MK). Bullimore¹⁴¹ conducted a review of the incidence of these CL-related complications in studies of soft CL wear in children, establishing across three large prospective studies representing between 159 and 723 patient-years of soft CL wear in patients aged 8–14 years, that the incidence of CIEs was up to 136 per 10,000 years.^69,141–143 A similar CIE incidence of 116 per 10,000 years was found in the 3-year clinical trial of MiSight® (CooperVision, US),¹²⁷ with no serious CL-related adverse events or significant biomicroscopy changes after 6 years of lens wear.³⁸ This compares to a rate of between 300 and 400 per 10,000 years in CL-wearing adults.^144,145 The incidence of CIEs varies with age; a large retrospective observational chart review established a CIE incidence of 335 per 10,000 years for teenagers (13–17 years) and 97 per 10,000 years in children (8–12 years).^54,146

In his review, Bullimore⁵⁴ concluded that the incidence of MK is no higher in the available studies than that found in adults; one retrospective chart review reported an incidence of 15 per 10,000 years in teenagers (13–17 years), with no MK in the younger age group (8–12 years). No cases of MK were reported in any of the prospective studies included in the review.¹⁴¹ Similar rates of adverse events to adult CL wear were found in a retrospective chart review that included data from real-world clinical practice, with the incidence of MK among 2,713 years of soft CL wear among children being 7.4 per 10,000 years.¹⁴⁷

Less information is available on CL-fitting practices in children. Fit data collected by the International Prescribing Report collated for the US for a 13-year period (2002–2014) showed just 11% of the more than 7,000 recorded fits during this time were to children up to the age of 15.¹⁴⁸ While the prevalence of ametropia requiring vision correction needs to be borne in mind when assessing if this proportion of CL fits is lower than expected, given the global increase in myopia, the number of young children requiring vision correction is only set to increase. A survey of US practitioners conducted in 2011 found that the preferred method of vision correction for younger children was spectacles, with CLs considered as a secondary option.¹⁴⁹ However, by early teenage years (13–14 years), nearly half of the practitioners (49%) began prescribing CLs as a principal form of vision correction.

Of interest was a change in fit behaviour noted, with 21% of those surveyed more likely to fit those aged 10–12 in CLs than they were a year prior, with reasons given at the time including the use of daily disposable lenses, improved CL materials and requests from either the child or the parent.¹⁴⁹ Use of daily disposables has been recognised as a particularly suitable modality for children due to the lack of care system and CL case, and overall fewer steps required in the daily routine, and was the most commonly prescribed modality to children aged 6–12 years in a survey of 38 countries between 2005 and 2009.¹⁵⁰ Further evidence of changing practice comes from a survey of 1,336 practitioners from five continents regarding their management strategies and attitudes towards myopia management.¹⁵¹ While the majority of young progressing myopes were still prescribed spectacles (39.3 ± 30.0%) or single-vision soft CLs (12.3 ± 15.5%) in 2019, this did reflect a shift in practice from the original 2015 data (spectacles, 47.8 ± 31.7%; single-vision soft CLs, 15.2 ± 17.3%).¹⁵² The minimum age that practitioners considered children were suitable for specific myopia control soft CLs ranged from 7.8 years in Europe to 10.8 years in Asia.¹⁵¹

The available evidence suggests that young children do well with CL, can be fit successfully and their relative safety is at least on par with adult wearers. Given that two myopia management options involve the use of specifically designed CLs, this information is reassuring. The age at which myopia occurs necessitating use of myopia management interventions may be lower than the previous average age at which practitioners felt comfortable offering CLs. Over time, the need for myopia management may be the driver to lower the age at which CLs are routinely suggested to young patients.

Multifocal fitting is not successful

The difficulty in achieving successful fits for presbyopes was a myth addressed by Efron and colleagues^3,4 in their original paper, with success rates as high as 80% being reported in the early 1990s and mention of correction methods including monovision, soft multifocals and a variety of rigid gas-permeable designs.⁴ Despite these early reports, CL fitting remains relatively low in this age group, and worldwide there is a low rate of CL prescribing to the presbyopic population demographic.¹⁵³ Population predictions show that the numbers of presbyopes will continue to grow. Today, presbyopes are more active than their predecessors^154,155; they want to feel young and not be limited by their presbyopia. Some individuals may also have work or social interests which make the head position and gaze requirements associated with spectacles not ideal. Thus, fitting presbyopes with lenses represents an excellent opportunity for growth within optometric practice and can provide wearers with substantial quality-of-life benefits.¹⁵⁶

So, why is the rate of presbyopic CL fitting so low? Practitioners report feeling that they lack the requisite knowledge to fit the lenses, that fitting presbyopes takes more chair time and that success rates are simply too low to bother spending the time and effort.¹⁵⁷ There are also concerns about dropout in this population, with 1-year retention rates dropping from 87% in the 16–24 age group to 64% in the 60+ age group,⁹⁸ primarily through reports of dryness, discomfort and poor vision.^97,98 Thus, it appears that the fear of failing to obtain a satisfactory result in a reasonable time frame and that multiple visits will be required to solve later issues are hindering practitioners from offering presbyopic CL options. Are these concerns valid, and, if so, how can they be addressed and overcome?

Advancements in optical design and manufacturing methods have resulted in an impressive array of varying power profiles, materials and frequency of replacement, with many soft lenses now being available in hydrogel and SiHy materials and in daily disposable offerings. Once committed to fitting the presbyope, practitioners need to decide whether they will opt for single-vision distance lenses with over-readers, monovision or full presbyopic correction. Reviews that are outside the scope of this article^158–163 detail the multifocal designs available. These new designs and material innovations have likely contributed to the increase in presbyopic CL prescribing in recent years,^148,164 but presbyopic CL modalities are still sparsely prescribed around the world. A recent global survey showed that within the presbyopic population 38% of wearers were fit with a single-vision distance correction, 10% with monovision and only 52% with a multifocal correction.³⁰ This is unfortunate as requiring over-readers is obviously inconvenient and binocular contrast sensitivity function is reduced along with stereopsis when monovision is employed.^165–167 When wearers have experienced both modes of correction, most prefer multifocals to monovision.^155,166

There are a number of ‘clinical pearls’ cited for successful multifocal fitting. The first point is to ensure that the patient has an up-to-date refraction and that any astigmatic component is considered as that will ultimately reduce the visual acuity obtained at both distance and near. Each multifocal design behaves differently on eye, and it is important that practitioners have a number of designs available from various manufacturers as what works on one patient may not be successful on another.^160,168,169 Manufacturers typically produce fit guides specific to each multifocal product, and increasingly, online applications or ‘calculators’ are becoming available that can suggest the most appropriate starting prescription based on information such as the up-to-date refraction and sensory ocular dominance. These ‘calculators’ can calculate spherical equivalence and compensate for vertex distance, thus eliminating many of the common errors that can limit success. One such online tool for a soft multifocal design was shown to agree with the final chosen practitioner prescription in 82% of eyes (within 0.25D) and in 96% eyes (within 0.50D).¹⁷⁰ It is very important that practitioners use these aids and follow their suggestions if they are to maximise the chance of success and minimise the time required to fit the lenses.

Another critically important point relates to centration of the lens; many of these lenses employ aspheric optics and decentration can induce significant amounts of off-axis aberrations, resulting in reduced quality of vision, which is especially important in subjects with larger pupils. An association between lens decentration and reduced vision was found in subjects where lenses were most decentred.¹⁷¹ Slit lamp assessment is adequate, but using a topographer over the lens to view any decentration can be valuable.¹⁷²

The final important point relates to the ways in which vision is assessed during the fitting. Standard visual acuity methods employed when fitting single-vision or toric lenses are less useful when fitting multifocal lenses. This poses something of a problem to the practitioner who usually relies on these simple, standardised methods as they do not offer them a method of quickly determining the likelihood of success with multifocals. Studies have demonstrated that the best predictors of success include asking patients to undertake more ‘practical tests’ such as reading their cell-phone, going shopping or using the lenses in their natural environment, rather than merely predicting success based upon visual acuity measures in the consulting room at the time of fitting; using subjective rating tools may further aid practitioners to gauge success when fitting multifocal lenses.^{154,155,168,173,174}

In conclusion, practitioner reticence to fit presbyopes with multifocal lenses misses a significant growth opportunity and contemporary multifocal lenses are certainly more successful now than 30 years ago and concerns about fitting this age group with lenses are outdated.

Concerns about CL-related complications, especially in non-compliant patients

Thirty years ago Efron and colleagues^3,4 examined the rate of CL-related complications by comparing them with the risks of complications from other forms of vision correction such as spectacles and refractive surgery, concluding that the already low risk of infection with CL wear could be lowered further by using lenses on a daily wear basis only.⁴ The recent BCLA CLEAR Complications report defines a CL-related complication as ‘an event caused by CL wear, which is generally symptomatic, causing the wearer to seek care, or requiring intervention, such as an interruption to CL wear or pharmacological intervention’.⁵⁰ Those complications cover a wide spectrum of conditions and can be grouped into infective conditions, inflammatory events, metabolic conditions, mechanical changes, toxic and allergic disorders, tear resurfacing disorders or CL discomfort.⁵⁰ CL-related complications are relatively common, experienced by roughly one-third of wearers, although most are mild and easily managed.⁵⁰

When addressing the concern of CL complications in non-compliant wearers, it is helpful to consider the incidence of non-compliant behaviour, how that behaviour may impact the risk of developing complications and actions that can be taken to lower those risks.

Although the individual steps in correct wear and care of CLs are simple and quick, when broken down, from correct hand washing, through to application, removal and, for reusable lenses, cleaning there are nearly 50 steps.¹⁷⁵ Correct case cleaning, timely replacement of both the case and lenses and avoidance of modifiable risk factors such as sleeping in lenses and water contact are in addition to that. Detailed in such a way it is not surprising that surveys reveal very few wearers are fully compliant to every process,^176,177 with a survey of nearly 1,000 wearers in the US establishing 99% reported at least one non-compliant habit associated with increased risk of infection or inflammation.¹⁷⁸

Although non-compliant behaviours are common, and can impact satisfaction with lens wear and comfort,¹⁷⁹ a review of over 4,000 visits from 1,276 CL wearers found that 82% did not present with any complications during a 2-year period.¹⁸⁰ The incidence of both CIEs and MK is well established, with an annual incidence of around 3% for symptomatic CIEs with daily reusable wear, and near 0% for daily disposable wear.⁶⁹ Wearing modality, not soft lens material, impacts the annual incidence of MK, with 2 per 10,000 for daily soft lens wear,^181,182 and approximately 20 per 10,000 for overnight wear.^181–184

Several extensive reviews on the topic of non-compliance (or poor adherence to practitioner advice) exist, and interested readers are referred to these for more details.^20,185–190 However, of the array of non-compliant behaviours that patients may undertake, several can be addressed during the time that the practitioner is taking the initial history and symptoms that truly can impact CL safety and performance. These include:

• Sleeping in CLs. This remains one of the most commonly reported non-compliant behaviours, with one of the greatest impacts, as sleeping in lenses (even occasionally) significantly increases the risk of MK by a factor of 10×,^{48,181–183,191,192} and the behaviour occurs even when patients acknowledge that ‘infection’ is a potential consequence.¹⁹³ This level of non-compliance is substantial, with one study reporting that only one-third of patients never ‘slept’ while wearing their lenses, 51% napped in their lenses, 9% occasionally slept in their lenses, 1% frequently slept in their lenses and 6% slept in their lenses almost every night.¹⁷⁷

• Non-compliance with the prescribed replacement frequency. Wearing lenses for longer than recommended before replacement is associated with a greater risk of CL-related complications^{177,194–196} and inferior performance with respect to comfort and vision.¹⁹⁷

• Failure to wash hands prior to handling lenses. Research indicates that 11–49% of patients fail to wash their hands before handling their lenses^198–201 and that there is an increased risk of 1.5 times for developing MK and 2 times greater risk for developing sterile keratitis in patients who fail to wash their hands.^51,181,192

• Impact of water exposure. Substantial evidence exists on the risk of developing both MK and CIEs in patients who expose their lenses to tap water, through direct exposure as well as indirect exposure through showering and hot tubs.^188,202,203

• Topping up the care system. Adding new solution to the lens case rather than disposing of the previously used solution and using entirely new solution has been linked to the development of serious complications.^{195,204–206} In one study, 22% of wearers report topping up their lens case occasionally, frequently or almost every night.¹⁷⁷

• Inadequate case cleaning and replacement. Another major factor related to CL-associated complications relates to inappropriate case hygiene.^{186,190,198,207,208} Failure to clean lens cases daily has been reported in 61–79% of contact lens wearers,^177,190,201 and failure to replace lens cases at least every 6 months is reported by 22–63% of wearers.^177,190,201

It is clear that non-compliant behaviours can result in serious complications for CL wearers – and patients may not always be aware of this. It is therefore extremely important for practitioners to strive to improve adherence among their patients and to help them to modify their CL wear and care procedures by regular reinforcement of relevant instructions. Taking the opportunity at every follow-up to discuss the many and varied opportunities for non-compliance and consideration of retraining the wearer, educating them of the relevant risks associated with poor compliance and potentially moving to daily disposable lenses that avoid several of these issues are very worthwhile.

Patients with low astigmatism do fine with spherical lenses

In relation to soft CL fitting, low astigmatism is typically defined as starting from 0.75D. This is the often-stated level at which it is suggested that soft toric lens designs should be considered.²⁰⁹ Leaving 1.00D of astigmatism uncorrected has been shown to impact a number of aspects of vision, decreasing both distance and near acuity by a significant amount,²¹⁰ and negatively impacting reading speed,²¹⁰ reading fluency²¹¹ and stereoacuity.²¹² Viewing a computer screen with experimentally induced astigmatism increases discomfort, blurred vision and headache.²¹³ Improved ocular comfort scores are correlated with visual quality in soft toric lenses,¹²⁵ and leaving astigmatism uncorrected can result in headaches, and increased symptoms of ocular discomfort and dry eye.^210,211

The ultimate result of dissatisfaction with vision in CLs is dropout. Astigmats are over-represented in the numbers of CL dropouts,^214,215 which perhaps suggests their visual needs are not being fully met. Dissatisfaction with vision is cited as a reason for ceasing wear by both experienced lens wearers²¹⁵ and new CL wearers within the first year of being fit.^98,99 In fact, it is important to consider that poor vision (41%) was found to be a more common reason for dropout of new wearers in a 12-month prospective study than reports of discomfort (36%).⁹⁹

Early hydrogel and SiHy soft toric lens designs were not without their limitations, which included inadequate²¹⁶ and unpredictable²¹⁷ fitting characteristics, along with a lack of rotational stability with both blink²¹⁸ and head position.^219,220 Thus, poor vision and comfort were not unexpected end results for many patients. With concerns surrounding early toric designs, it is possible to see where correction of the low astigmat with a spherical lens originates. In fact, concerns about the difficulty of correcting astigmatism with CL were cited in the original review of Efron and colleagues⁴ of almost 30 years ago. Previous popularly held beliefs that a thick, soft lens could ‘mask’ low levels of astigmatism.^221–224 or that aspheric lens designs could improve visual outcomes in low astigmats compared to toric corrections^225,226 have subsequently both been shown to not be true.

In fact, when compared with spherical lenses, the benefits of soft toric CLs include significantly improved subjective and objective visual performance,^227–229 with greater comfort reported when viewing a computer screen.²¹³ Naturally, to be confident in their use, practitioners must be able to trust that the product requires minimal chair time to achieve a successful fit, and that it can deliver stable, clear vision for the patient. Across a number of different proprietary designs, modern soft toric CL designs appear to be able to achieve this. They are as quick to fit as spherical lenses,²³⁰ and high rates of fit success with soft toric lenses have been reported for the refitting of spherical lens wearers (80%), previous CL dropouts (75%) and neophytes (70%).²³¹ High levels of performance have been shown for high contrast acuity, rotational stability and performance in real-world visual tasks of modern soft toric lenses.^{219,220,232–234}

The progress achieved in the design, manufacture and overall performance of soft toric CLs over the last three decades is clear, with a wide choice now available of different materials, modalities and stabilisation methods. Prescription coverage is high too, with some ranges of frequent replacement soft toric CLs covering up to 96.4% of prescriptions found in a typical clinical population.²³⁵ Given these facts, how widely do practitioners embrace the use of soft torics? The most recent International Contact Lens Prescribing Report finds around one-quarter of all soft lenses fit were soft torics (27%), compared to one half for spherical lenses (51%), with other soft lens designs and fitting methods (multifocal; monovision; myopia control; cosmetic) making up the remainder.³⁰ When comparing the proportion of soft torics to spherical lens fits only, the 5-year average from 25 countries consistently reporting data is 37%, with variation by country from 9% in Russia to 54% in Switzerland.^30,236–239 The average figure of 37% appears to compare well with estimates of clinically significant astigmatism (≥0.75D) in the literature. A systematic review of 34 manuscripts examining astigmatism in more than 120,000 adults found an average global prevalence of 40.4% of this level of astigmatism.²⁴⁰ This compares closely with analysis of data from clinical populations in the US, the UK and Canada, where 41% of eyes were found to have at least 0.75D of astigmatism.²³⁵

Given these data, it could be argued that the long-held belief that low astigmats do not benefit from full correction in CL is no longer widely held. With the exception of some countries, it seems likely that a relatively small number of practitioners returning fit data to the international prescribing report are close to offering soft torics to the vast majority of astigmatic patients they see. What remains now is to ensure the remaining majority of practitioners in each country embrace the same proactive approach, to ensure all astigmats, including low astigmats, are offered the benefits afforded by full astigmatic correction in their CL.

Business-focused barriers

Focusing on growing my CL business is too time-consuming

It is important to recognise that CL practice forms only one part of the routine clinical practice for practitioners to consider. The means that the amount of time taken to find interested patients, to create time in the clinic diary to fit them and teach them wear and care are relevant concerns. Balancing these demands with routine eye care and income revenues for chargeable in-office treatments and spectacle dispensing can seem challenging. Indeed, the concern about the profitability of CLs was present three decades ago, with reassurances given by Efron and colleagues⁴ about the continuing need CL wearers have for spectacles, their increased contact with the practice for aftercare visits and the potential to include care systems in the CL package as an additional revenue stream.

The first step to growing the CL business is to fit more patients with CLs. A 2018 survey of dual wearers (CLs and spectacles, n = 175) and spectacle-only wearers (n = 104) found that in both groups the majority expected their practitioner to advise them about the suitability for CLs (dual wearers 80%, spectacle wearers 64%).²⁴¹ However, these subjects recalled that their practitioner only recommended CLs to them less than a third of the time (31%).²⁴¹ These data agree with anecdotal reports of the disconnect between practitioners expecting interested patients to ask for CLs, but patients waiting for the professional recommendation about their suitability for CL wear to come from their practitioner. The importance of proactive recommendation of CLs has been demonstrated, with studies conducted over a quarter of a century ago reporting a significant increase in CL trials and purchase by simply recommending the option to all suitable patients.^242–244 Given the results of Draper et al. regarding the relatively low proportion of practitioners making CL recommendations, it is interesting to note that the apparent simplicity of a proactive approach to CL fitting has not necessarily permeated into the routinely practiced behaviour for all practitioners.

Additional concerns that may prevent a proactive recommendation for all patients relate to the time taken to fit this into practice, and also to concerns about reducing spectacles sales. Two studies address both of these points through demonstration of a novel approach to delivering an on-eye CL experience. Conducted initially in the UK under the name ‘Enhancing the Approach to Selecting Eyewear (EASE)’,²⁴⁵ and followed up by a similar approach in the US,²⁴⁶ the protocol specifically did not ask subjects initially if they wished to wear CLs. It removed that sense of a decision or commitment, instead using an on-eye CL experience as an aid to help each subject see themselves more clearly when selecting new spectacle frames. The results demonstrated all-round benefits, with subjects spending up to 32% more on their spectacles, and reporting higher levels of satisfaction with their dispensing experience.^245,246 Between 63% and 88% agreed to try CLs after this initial experience, were greater than 2.5 times more likely to have had, or have scheduled, a full CL fit,²⁴⁶ and 2.5x more subjects eventually purchased CLs.²⁴⁵

Concerns about chair time taken to fit soft CLs have been addressed in earlier sections of this manuscript for young children, presbyopes and when fitting soft torics. Chair time can further be reduced by simple steps in practice such as gathering potential diagnostic lenses ahead of the appointment of a patient for routine soft CL fits and ensuring wear and care training can be delegated to trained members of the practice team.

Naturally, there will always be pressures on time and revenue in a clinical practice. To maximise the opportunity for CLs, the evidence continues to suggest more can be done to be proactive and routinely mention CL suitability to all age groups. Combining a CL experience with spectacle frame selection results in an improved patient experience, and many contemporary CL designs provide high levels of fit success to help minimise chair time.

My CL business will not grow because as many patients as I fit end up dropping out

The concern that CL-related dry eye was an intractable problem was one of the myths Efron and colleagues⁴ addressed three decades ago, with new polymer technologies, use of punctal plugs and humidifiers being suggested as possible solutions. A recent literature review established an average dropout frequency in developed countries of 21.7% (range 12.0–27.4%), noting that nearly three-quarters (74%) can be successfully fit again.²⁴⁷ The most commonly cited reasons for ceasing CL wear, particularly in established wearers, are dryness and discomfort, particularly at the end of the day.^96,214 It is perhaps worth noting that these surveys were conducted over a decade ago, and since that time many more new CL materials have become available.

More recent data from newly fit CL wearers established that whilst discomfort remained a common reason for ceasing wear within the first year of being fit (cited by 36% of dropouts), that vision-related issues, either poor distance or poor near vision, were more commonly given as a reason for stopping wear (41%).⁹⁹ Handling difficulties were also cited as a reason by a quarter of dropouts.⁹⁹ When data from new wearers was examined in a retrospective study, in spherical CL wearers, handling and comfort were the most commonly cited performance-related reasons for discontinuing; however, visual problems were the most common reason among new wearers of toric and multifocal CLs.⁹⁸

These insights provide valuable information to help practitioners prevent dropout and keep patients in CLs. Assessing levels of comfort performance is still key, with a need to establish a full picture of the patient experience during routine CL checks. It is known that wearers who experience CL discomfort will gradually reduce their hours and days of wear to help manage the limitation.^101,248 This may not be reported to the practitioner and can ultimately lead to a ‘quiet’ dropout that was not known about. One important point to consider relates to establishing both total and comfortable wear time and establishing whether there is a considerable gap between these two reported times.

Use of a validated questionnaire can quantify the patient experience. The Contact Lens Dry Eye Questionnaire (CLDEQ)-8 can inform practitioners when to intervene (score ≥12) and allows them to judge clinically important changes in comfort (score change of ±3).²⁴⁹ The Standardized Patient Evaluation of Eye Dryness (SPEED) questionnaire has also been assessed for its ability to detect dry eye symptoms in CL wearers.²⁵⁰ Where suboptimal comfort is reported, the practitioner can consider changes to the CL material, modality, care system and management of tear film quality, ocular surface and lid margin condition.^22,28

The importance of full and accurate vision correction should not be overlooked for any wearer, but it is particularly relevant for astigmats and presbyopes who are at greater risk of dropping out for this reason. When suboptimal vision is present, it may be resolved by a change in CL power; however, the importance of assessing, and improving where necessary, tear film quality should not be overlooked. In addition, evidence exists for reduced ocular aberrations in between blinking when wearing a CL material with an embedded wetting agent compared to the base material without a wetting agent.^251,252

For new wearers, it is important to pay close attention to handling. In the prospective study of new wearers, wear and care training was most commonly conducted in one-on-one sessions with support staff, with additional technology such as video or smartphone applications used just under half the time (46%).⁹⁹ The requirements for limiting contact in practice and practicing physical distancing demanded by the coronavirus pandemic²⁵³ have resulted in a rise in the use of telehealth and technology for patient care throughout 2020,²⁵⁴ a change that may well stay for many practices once the COVID-19-specific safety restrictions are lifted.

It is certainly beneficial to offer different resources for patients to access at home to help remind them of the steps for lens application, removal and care. Given that those who drop out due to handling issues most often do so with the first few weeks of wear,⁹⁹ early follow-up of the patient is advisable. However, only 12% of practices in the prospective new wearer study said they ‘always’ or ‘frequently’ contacted new wearers to check their progress.⁹⁹ Making this simple change to routine practice with a delegated member of staff calling new wearers after a few days can help to uncover and address any early difficulties.

Without a proactive approach, dropout will continue to occur. It is notable in the retrospective study of new wearers, of those who stopped wear, the reasons were unknown for nearly one in three wearers.⁹⁸ Maintaining patients in CL wear requires routine aftercare appointments, during which a full picture of the wear experience should be established. The practitioner needs to consider CL comfort, vision and handling, the likelihood of each issue varying with how long the patient has been in CLs, their refraction and ocular surface health. It can be helpful to educate the patient about the needs of ‘life long’ or long-term CL wear, making them aware that options often exist to help suboptimal performance, and that it is expected the type of lens best suited to a patient may change over time. This can help open the door to more open conversations with the practitioner and minimise the risk of the quiet dropout that is never brought to the attention of practitioners.

Discussion

Fitting and dropout data demonstrate that much more can be done to offer patients the opportunity to wear (and subsequently maintain wearing) CLs, providing them an excellent alternative vision correction option to their spectacles. The recent BCLA CLEAR reports promote the importance of practicing evidence-based fitting to maximise the chance of successful lens wear. The intention of this review was to address 10 commonly held beliefs that may impact the approach of practitioners to CL fitting.

Comparisons to the work of Efron and colleagues^3,4 of 30 years ago confirm that some beliefs (based on little or outdated evidence) remain (Table 2), illustrating just how challenging it can sometimes be to change behaviour. Good evidence exists across the 10 beliefs examined in this review that help to dispel or entirely debunk them. Oxygen delivery does not drive CL comfort, hydrogels have a role to play in contemporary practice, not all CL deposition should be considered undesirable and CL comfort can also be improved by improving the health of the lid margins and tear film.

Table 2. Summary of whether 10 common beliefs related to contemporary contact lens fitting are supported by evidence.

Group	Belief	Addressed in the 1992 reviews of Efron and colleagues^Citation3,Citation4	Does current evidence enable the belief to be labelled as a ‘myth’ for contemporary CL practice?
Related to the contact lens and care system	Increasing oxygen transmissibility improves lens comfort	Comfort/‘dry eye’ was addressed but not directly in relation to oxygen.	Myth.
	Hydrogels should no longer be fitted	No.	Myth.
	Patients will be more successful wearing contact lens materials that demonstrate low levels of deposition	No.	Myth.
	When a patient reports discomfort, the first – and most appropriate – option is to change the lens	No.	Myth.
Patient-related concerns	Young children are less successful with contact lenses	No.	Myth.
	Multifocal fitting is not successful	Yes.	Myth.
	Concerns about contact lens-related complications, especially in non-compliant patients	Yes.	No. It is true that non-compliant behaviours increase the risk of CL-related complications; however, those risks are modifiable and there are many options related to the type of lens fit and patient education that the practitioner can employ to mitigate those risks.
	Patients with low astigmatism do fine with spherical lenses	Yes. Discussed as vision being better with glasses than CLs.	Myth.
Business-focused barriers	Focusing on growing my contact lens business is too time-consuming	Yes. Discussed the concern that CL practice is not profitable.	Myth.
	My contact lens business will not grow because as many patients as I fit end up dropping out		Myth.

A substantial opportunity exists to be more proactive with offering CLs to young children (particularly when considering the need for myopia management), to low astigmats and to presbyopes. In all these groups, evidence confirms that modern soft lens designs are simple to fit, with successful outcomes possible with minimal impact on chair time. A proactive approach to CL fitting, coupled with ensuring patients continue to be satisfied with their lens performance, will help to grow the overall CL business for practitioners, while minimising dropout.

Perhaps the only ‘myth’ addressed here that has evidence to support it is related to CL complications and its link with patient compliance. It is true that wearers are often not fully compliant with all steps in their daily wear and care regimens, and it is true that non-compliant behaviours are associated with an increased risk of CL-related complications. However, these points certainly do not make CLs too risky to fit. What can be taken from the considerable evidence in this area is a deep understanding of the risk factors related to complications, and a reminder that the practitioner should educate their patients of these risks at every visit, along with recommendation of the most appropriate CL replacement frequency and cleaning regimen to help support those behaviours for each individual situation.

Practitioners have an ever-increasing range of CL designs and materials across different replacement frequencies to offer patients interested in becoming CL wearers and to then maintain them successfully in CLs over many years. Ensuring clinical practice follows the evidence base, which will change over time, is the most appropriate way to help many more patients access the benefits of CLs.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Karen Walsh: Over the past 3 years Karen Walsh has received honoraria from Alcon, CooperVision, and Johnson & Johnson Vision; Lyndon Jones: Over the past 3 years Dr Jones’ research group (CORE) or he personally has received research support or lectureship honoraria from Alcon, Allergan, CooperVision, GL Chemtec, iMed Pharma, J&J Vision, Lubris, Menicon, Nature’s Way, Novartis, Ote, PS Therapy, Safilens, Santen, Shire, SightGlass and Visioneering. Dr Jones is also a consultant and/or serves on an advisory board for Alcon, CooperVision, J&J Vision, Novartis and Ophtecs; Kurt Moody: Dr Moody is the Director of Professional Education North America at Johnson & Johnson Vision Care. This manuscript was supported through an educational grant from Johnson & Johnson Vision to the Centre for Ocular Research & Education (CORE) at the University of Waterloo.