A Study on the Change of Positive Vergence and Accommodative power according to Illumination

Abstract

Purpose: The purpose of this study is to investigate changes of positive vergence and accommodative power with illumination. Methods: 49 subjects(mean age:24.51±2.82) having no systemic and ocular disease were recruited. Illuminance environment is going to use the light meter ((LX-101, Lutron, USA) and dimmers to change the light intensity from 10 lux to 1000 lux measured the amplitude of accommodation and far/near positive vergence. Results: Amplitude of accommodation was lowest to 8.51 D with 10 lux and the highest to 9.12 D with 800 lux. As the illuminance increases, the exponential decay fit(y=9.09-0.62e-) was maintained while also increasing amplitude of accommodation. Break point of distance positive vergence was higher by 20.81 △ at low illuminance of 10 lux, near positive vergence was higher by 21.42 △ at low illuminance of 10 lux. The exponential decay fit of Distance/near positive vergence were y=17.08+4.66e- and y=20.93+0.63e- , respectively. Conclusions: As the illuminance increases while amplitude of accommodation is increasing, Distance/near positive vergence was increase in low light, while temporarily reduced while increasing illuminance showed a pattern that changes less.