NO CHANGES IN THE ACCOMMODATIVE STIMULUS-RESPONSE CURVE BUT VARIED LAG OF ACCOMMODATION AFTER A 30-MIN ELECTRONIC NEAR TASK UNDER FOUR DIFFERENT LIGHTING CONDITIONS AMONG MYOPIC YOUNG ADULTS

Abstract

The prevalence of myopia is increasing worldwide, mainly in Asian countries. Light-emitting diodes (LED) and low light levels used for homework after school was thought to contribute to myopia development. This study explored how near work and lighting affect the accommodation response. Thirty myopic young Malay adults (18-23 years old) were recruited. The ASRC was measured after performing a 30-min near the electronic task at 20cm using a binocular open-field autorefraction (Grand Seiko, Shin-Nippon) at 6.0 m, 1.0 m, 0.5 m, 0.33 m, 0.25 m, and 0.20 m under four different lighting conditions (Fluorescent 6500K, Fluorescent 3000K, LED 6500K, LED 3000K). A significant flattening in the ASRC gradient was noted when comparing pre and postmeasures following the near-vision task for all lighting conditions (p < 0.01). ASRC gradient differences were not affected by lighting conditions (One-way repeated measure ANOVA F (3,87) = 0.84, p > 0.05). ASRC gradient was affected only after 30 minutes of near work F (3,87) = 0.049, p < 0.05). The increment in the accommodative inaccuracy was apparent following prolonged close work. Types of light were not imperative. This information on short-term exposure can be useful for interior light choice of buildings. The effect of long-term exposure requires further investigation.