Amplitude of Accommodation

Alcohol consumption is a globally prevalent practice with well-documented systemic effects. However, its specific impact on visual performance, a critical component for tasks like driving, remains relatively under-investigated. This study aimed to investigate the effects of a standardized dose of alcohol on visual performance parameters. A single-blind, randomized study design was employed, and data were analyzed using the IBM Statistical Package for Social Sciences (SPSS) version 22.0, incorporating descriptive statistics and repeated measures ANOVA. The study comprised sixty participants (mean age 24.1 ± 2.8 years), randomly assigned to an Alcohol group (n = 30) that consumed 250ml of red wine (12% alcohol) or a Control group (n = 30) that consumed an equal volume of a matched placebo. Visual performance parameters, which includes visual acuity (distance and near), contrast sensitivity, amplitude of accommodation, and near point of convergence, were measured at baseline, 30 minutes, and 60 minutes post-consumption. The findings of this study showed that the consumption of alcohol induced a significant deterioration in visual function: distance visual acuity (LogMAR) worsened from a baseline of -0.06±0.14 to 4.29±1.50 at 30 minutes (p = 0.002), near visual acuity (N-notation) worsened from 0.02±0.05 to 3.40±0.67 (p = 0.003), amplitude of accommodation decreased from 13.20±3.40D to 9.83±3.01D (p = 0.001), and near point of convergence (break) receded from 5.50±3.93cm to 8.50±4.38cm (p = 0.003). In contrast, alcohol consumption did not produce a statistically significant effect on contrast sensitivity at any time point (p > 0.05). In conclusion, this study showed that acute, moderate alcohol intake significantly impairs key aspects of visual performance essential for depth perception and focusing. These findings hold clinical significance for optometry, providing evidence-based data to counsel patients on the specific visual risks of alcohol consumption, particularly for activities requiring precise oculomotor control and sharp vision, such as driving at night.

Body Mass Index (BMI) is a common indicator of nutritional and general health, but its possible effect on visual performance, especially binocular vision, has not been widely studied. This study investigated how BMI influences binocular vision parameters Near Point of Convergence (NPC) , Amplitude of Accommodation (AoA) , Heterophoria, and Fusional Vergence among healthy young adults. A descriptive cross-sectional study was conducted at the University of Benin Optometry Clinic involving 100 participants aged 17–30 years. Participants were grouped as underweight, normal, overweight, or obese based on the World Health Organization (WHO) BMI classification. NPC was measured with a meter rule, AoA using Donder’s push-up method, and both Heterophoria and Fusional Vergence assessed with a phoropter via the von Graefe technique. Data were analyzed using descriptive statistics and Pearson’s correlation at a 0.05 significance level. Results: BMI was significantly associated with NPC recovery (p = 0.047) but not NPC break (p = 0.121). AoA and Heterophoria showed no significant correlations with BMI (p = 0.529; p = 0.154/0.999). Negative Fusional Vergence (NFV) break at 6 m differed significantly across BMI groups (p = 0.043), whereas Decompensated Phoria did not (p = 0.249). BMI also showed a significant relationship with refractive status (p = 0.039),Over weight subject were more of myopic astigmatism and Obese Subject tended towards hyperopic astigmatism. Conclusion: Higher BMI appears to reduce convergence recovery and fusional divergence efficiency, though accommodation and heterophoria remain unaffected. This suggests that excess body weight may compromise oculomotor control through systemic or neuromuscular mechanisms. Incorporating BMI assessment into binocular vision evaluations is recommended to promote both ocular and general health.