A CUP OF CLARITY: EXPLORING THE EFFECTS OF CAFFEINE ON ACCOMMODATION, PUPIL DYNAMICS, AND OCULAR HEALTH

VEENU KUMARI¹, KRISHNASRI PADAMANDALA^1,2, SACHITANAND SINGH¹, ASHITH TRIPATHI¹, IQURA JAMAL KHAN¹

¹Department of Optometry, University Institute of Allied Health Sciences (UIAHS), Chandigarh University, Punjab – Gharuan, India.

² Department of Optometry, School of Allied and Health Care Sciences, Mallareddy University, Maisammaguda, Telangana, India.

Review Article

SALT Journal of Scientific Research in Healthcare, Volume 6, Issue 1, Page 9-i, Published on 25th June 2026, https://doi.org/10.56735/saltjsrh.ms26060109i

ABSTRACT

Purpose: Caffeine is a widely consumed stimulant that impacts various body systems, including the visual system. The study explores the impact of caffeine on vision performance and health through a structured evaluation of its effects on visual function.

Design: This study is a review article designed as a systematized narrative review based on published literatures, to evaluate the effects of caffeine on ocular and visual functions. The main areas explored included pupil size, IOP, accommodation, reading performance, and visual acuity using a conceptual review approach. A literature search was performed using websites like PubMed, Google Scholar, and Research Gate.

Methodology: Used keywords: caffeine, amplitude of accommodation, pupil size, and ocular health. We only included research articles written in the English language, including human participants with caffeine administration.

Results: A total of 18 studies meeting our study criteria were found after importing studies through a database search. The methodology of 18 studies was included out of which two studies were experimental, one was clinical study and the other six were prospective cross-sectional. The magnitude and duration of the caffeine effect vary based on dosage, individual differences, and drink type. While some studies report a slight increase in pupil size and AA, the evidence is less consistent.

Conclusion: Current review emphasizes on normal individuals provides information about how caffeine increases visual accommodation and reading speed, causes pupil dilation, and changes choroidal thickness, which all can alter the clarity of vision in certain conditions. Such research could suggest the need for controlled investigations with steady caffeine dosages to advance knowledge and inform public health practice about the consumption of caffeine.

Keywords: Caffeine, Accommodation, Pupil, Ocular, Eye Diseases