Refractive error among commercial drivers : Indian Journal of Ophthalmology

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Refractive error among commercial drivers

Sutar, Samir; Agarwal, Pradeep1

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Indian Journal of Ophthalmology 71(2):p 671, February 2023. | DOI: 10.4103/ijo.IJO_1836_22
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Dear Editor,

The authors of the article titled “Refractive error among commercial drivers,”[1] Kumar et al.,[1] have put forth a number of interesting points. I would like to congratulate the authors on the same.

While driving, vision is the most crucial source of information, and visual issues have been linked to numerous driving-related injuries. In real life, there is a vivid sense of three-dimensionalities and four different forms of vision (form vision, color vision, depth vision, and motion vision) need to be continuously processed by the visual neurological system, as reported in another study.[2] However, the authors have mentioned in their study that color vision assessment was done under binocular viewing conditions, but historically, color perception tests have been conducted monocularly. Previously reported literature has also shown that binocular viewing may lead to over-perception of color vision.[3] The authors should have used HRR pseudoisochromatic plate instead of Ishihara pseudoisochromatic plate to detect congenital and acquired colour vision impairments. Considering that the ishihara colour vision chart is just intended for screening and not for diagnosis. Similarly, the authors have chosen the housefly stereo test for depth perception; however, the housefly stereo test can predict gross stereopsis, not fine. Authors have defined depth perception by using gross stereopsis in their study, which is slightly biased. The randot stereo optical test could have been employed by the authors instead of the house fly stereo test. However finding a stereo-deficiency would be a much better option with randot stereo-optical test because this can defined fine steropsis. A previous study reported that stereo acuity also plays an important role in driving skills.[4] It would be fantastic for the society of commercial drivers if the authors could organize additional research in this field to determine the impact of stereopsis anomalies on RTA in a much bigger driver population. As contrast sensitivity also plays an important role in driving skills, before an eye issue impacts a patient’s ability to drive, visual screening with CS can help detect ophthalmic illnesses early.[5]

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1. Kumar M, Mahaseth A, Parveen S, Rafeeq U, Chauhan L. Refractive errors among commercial drivers Indian J Ophthalmol 2022;70:2112–6.
2. Honavar SG. Driving blind-Should tests of visual function be mandatory for driving license? Indian J Ophthalmol 2019;67:193–4.
3. Opper JK, Volbrecht VJ. Binocular vs. monocular hue perception Vision Res 2017;131:1–15.
4. Bauer A, Dietz K, Kolling G, Hart W, Schiefer U. The relevance of stereopsis for motorists:A pilot study Graefes Arch Clin Exp Ophthalmol 2001;239:400–6.
5. Spreng L, Favrat B, Borruat F-X, Vaucher P. Cross-sectional study assessing the addition of contrast sensitivity to visual acuity when testing for fitness to drive BMJ Open 2018;8:e018546.
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