Effects of caffeine on near vision of healthy subjects in Benin metropolis

Abstract

To determine the effect of oral consumption of different concentrations of caffeine on near vision, thirty (30) healthy volunteers consisting of fifteen males and fifteen females were used for the study. The subjects were aged
between 19-30 years with a mean age of 24.2±2.9 years. They were all non-habitual consumers of coffee and non- smokers of cigarettes. The subjects were all emmetropes and had no history of any systemic or ocular pathologies. For the purpose of the study, the subjects were divided into 2 groups (A and B) of 15 subjects each, to which 2 different concentrations of caffeine (100mg and 200mg ) was administered. The near vision was assessed by measuring the amplitude of accommodation (A of A) and near point of convergence (NPC) of the subjects using the Royal Airforce
(RAF) rule. The measurements were taken before, and then, after 30, 60 and 90minutes of oral consumption of 100mg and 200mg concentrations of caffeine solutions respectively. Statistical analysis of the data was carried out using ANOVA and T-test, where it was discovered that the consumption of the two concentrations of caffeine caused a significant change in the mean A of A and NPC (P<0.05). Thus the consumption of certain concentration of caffeine has the capacity to adversely affect near vision.