Nearpoint Phorias After Nearwork Predict ADHD Symptoms in College Students

Abstract

Phorometric findings have been observed to change with stress. We test the hypothesis that postnearwork phorias predict symptoms that have been theorized to result from nearwork-induced visual stress. We measured nearpoint and farpoint dissociated phorias in 37 unselected college students with an alternate cover test both before and after a challenging reading comprehension test. We also assessed a broad range of putative attention deficit hyperactivity disorder (ADHD)-related symptoms with the Nadeau College-level ADHD Questionnaire. For phorias measured at nearpoint after nearwork, greater deviation from the median phoria (three exophoria) predicted higher symptoms (rho (35) = 0.52, p < 0.001), whether that deviation was in a convergent or a divergent direction (both rho's (18) = >0.48, p's < 0.04). An analogous result was obtained for "distance-near" stimulus accommodative convergence to accommodation (AC/A) ratios calculated from phorias, where greater deviation from median postnearwork AC/A ratio predicted higher symptoms (rho (35) = 0.52, p < 0.0001). Symptoms did not correlate with prenearwork phorias, prenearwork AC/A ratios, or postnearwork farpoint phorias (p's > 0.05). Phorias postnearwork, but not prenearwork, predicted self-reported ADHD-related symptoms in college students. These results link binocular imbalance immediately after sustained nearwork to symptoms theorized to result from nearwork-induced visual stress.