Date of Award
Master of Science in Vision Science
Purpose: The purpose of this study is to examine the effects of caffeine on visual performance of the eye among normal healthy adults.
Methods: This two-visit randomized placebo-controlled crossover study included 49 normal healthy adults aged 18 years and above who received either 200mg of caffeine or placebo capsules. Choroidal thickness, tear break-up time, accommodative power, pupil size and reading performance were assessed at baseline, 1 hour and 2 hours.
Results:Consumption of caffeine showed an increased effect on reading rate (p<0.05), average span of recognition and tear break up time (p=0.05) at 1 hour. There was no significant difference seen between the caffeine and placebo group in choroidal thickness (p=0.547), pupil size (p=0.137) and accommodative power (p=0.860). All the aforementioned metrics were not significant at 2 hours. Average span of recognition has a good correlation (r=0.855, p<0.01) with reading rate that was significant at 1 hour among the caffeine group.
Conclusion: Caffeine consumption has some effect on visual performance of the eye by increasing reading rate and tear film quality. This transient effect peaks at the 1 hour mark and can potentially help an individual have better quality of vision to improve their visual performance for near tasks.
Murari, Swetha; Ho, Amiee; Hayes, John; and Cooper, Scott, "Effects of caffeine intake on visual performance of the eye among normal healthy adults" (2018). College of Optometry. 842.