Effect of Caffeine on Contrast Sensitivity among Young Adults of Abia State University

Abstract

Introduction: Caffeine is the most widely consumed psychoactive substance. Unlike many other psychoactive substances, it is legal and unregulated in the world. Several experts suggest that moderate use of caffeine (300 mg or equivalent to 3 cups or less to regular size cups of coffee per day) is safe and so not likely to cause health issues. Intake of caffeine has been suggested to affect the visual system. This study examined the effect of consumption of caffeine on contrast sensitivity of the eye among young adults of Abia State University students within the age range of 17-30 yrs. Methods: This study employed a cross-sectional design and was carried out within the confinement of Abia State University Eye Clinic. A total of 100 young adults consisting of an equal number of males and females were measured using the Rabin’s contrast sensitivity at baseline, 30 mins until 120 mins. One way analysis of variance (ANOVA) and the Chi-square statistical analysis was used to analyze statistically the research hypotheses at 95% level of significance. Results: The findings of this study reveal that mean contrast sensitivity values for 16 to less than 20 years old were 1.70 at baseline and increased to 1.79, 1.89, 1.93 except at 120 minutes post-ingestion of caffeine. In males and females, contrast sensitivity increased by 1.57%, 3.7%, 5.3% and 10.7%, 20.7% 23.3% respectively. At 95% confidence level, caffeine ingestion had a significant effect on contrast sensitivity for both males (4.79) and females (5.8). Conclusion: This study depicts that the ingestion of caffeine affects or increases contrast sensitivity in both males and females although this effect is short-lived.