Should myopic students wear eyeglasses?―A regression-discontinuity analysis

ABSTRACT

Despite the high prevalence of myopia among school-age children in China, many myopic students are reluctant to wear eyeglasses. This study estimates the effects of wearing eyeglasses on myopic students’ academic performance, using data from a large-scale survey of middle-school students, the China Education Panel Survey. Our fuzzy regression discontinuity (RD) design, which exploits the jump in the probability of wearing eyeglasses at the threshold for myopia diagnosis, reveals that wearing eyeglasses improves myopic students’ Chinese and maths test scores by 0.27 and 0.24 standard deviations, respectively.

KEYWORDS:

• Vision
• eyeglasses
• regression discontinuity design
• education
• China

JEL CLASSIFICATION:

• I18
• I21

Acknowledgments

This work was financially supported by the 2115 Talent Development Program of China Agricultural University and the National Natural Science Foundation of China [grant number 71973134].

Disclosure statement

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

Notes

¹ This scale can be converted into the U.S. scale using $V=5.0-\mathrm{l}\mathrm{o}\mathrm{g}\left(d/D\right)$, where d/D is the U.S. measure of visual acuity: d is the vision-screening distance in feet; D is the distance at which someone with normal vision can see a given object clearly. The threshold for normal vision is $\frac{d}{D}=\frac{20}{20}$, meaning that a person can see an object from 20 feet away as clearly as anyone with normal vision from the same distance (Kniestedt and Stamper 2003).

² To verify this, we ran a regression of an indicator 1(V = 5.0) on the full set of observed characteristics, using observations within the V $\in$ [4.9, 5.1] interval. None of these characteristics came out statistically significant.

³ We thank an anonymous reviewer for suggesting adding explanations of these effects.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [71973134].