Original Research

The refractive behaviour of the human eye under different ambient lighting conditions

Thokozile I. Metsing, Anthony Carlson
African Vision and Eye Health | Vol 82, No 1 | a839 | DOI: https://doi.org/10.4102/aveh.v82i1.839 | © 2023 Thokozile I. Metsing, Anthony Carlson | This work is licensed under CC Attribution 4.0
Submitted: 08 February 2023 | Published: 28 September 2023

About the author(s)

Thokozile I. Metsing, Department of Optometry, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa
Anthony Carlson, Department of Optometry, Faculty of Health Sciences, University of Johannesburg, Johannesburg, South Africa

Abstract

Background: Adjustment of the ocular accommodative system is an important phenomenon allowing for optimal vision at different distances.

Aim: The study compared the refractive behaviour of the human eye under different ambient lighting conditions for different target brightness.

Setting: Auto-refraction measurements were taken of the participants in the Department of Optometry at the University of Johannesburg.

Methods: Five African participants from a single ethnic group aged between 20 years and 25 years, had 40 successive auto-refractor (Nidek AR 610) measurements taken on the right eye of each participant in a bright and dark room using the illuminated and dark targets (LL and DL); dark target in the illuminated and dark room (LD and DD).

Results: A change in the refractive state of all participants was observed on LL and LD, except for one, who experienced myopic shifts. The largest significant difference in the variance-covariances and the means was approximately 2.40 dioptre (D). The other participants’ shifts in means were approximately the same and varied between 1.00 D and 1.50 D stigmatic shift. For the DL to DD conditions all participants, except for one, underwent a hyperopic shift of about 0.50 D.

Conclusion: The refractive behaviour of the human eye appears to be dependent on ambient light conditions as well as target illumination or luminance.

Contribution: The study is scientific and clinical, and focuses on changes in refractive behaviour under different lighting conditions, falling within the scope of the journal. Key insights are that there is a change in the refractive behaviour of the eye under different ambient conditions.



Keywords

refractive behaviour; auto-refractors; luminance; photoreceptors; depth of focus; stereo-pair scatter plots

Sustainable Development Goal

Goal 3: Good health and well-being

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