Effects of Retinal Illuminance on Visual Acuity and Fusion.

Kim, Nam Soo; Lee, Ji Hoon; Chang, Yoon Hee; Lee, Jong Bok

Original Article

Journal of the Korean Ophthalmological Society 2002;43(2):332-336.
Published online February 1, 2002.

Effects of Retinal Illuminance on Visual Acuity and Fusion.

Nam Soo Kim, Ji Hoon Lee, Yoon Hee Chang, Jong Bok Lee

¹The Institute of Vision Reserch, College of Medicine, Yonsei University, Seoul, Korea.
²Department of Ophthalmology, College of Medicine, Yonsei University, Seoul, Korea. 491209@yumc.yonsei.ac.kr

망막 조도 변화가 시력과 융합에 미치는 영향

김남수 ( Nam Soo Kim ) , 이지훈 ( Ji Hoon Lee ) , 장윤희 ( Yoon Hee Chang ) , 이종복 ( Jong Bok Lee )

Abstract

PURPOSE
We examined the effects of induced retinal illuminance on visual acuity and fusion. METHODS: Fifty adults with best corrected visual acuity of 20/20 or better and normal binocularity and fusion were examined. To examine the effect of retinal illuminance on visual acuity and the effect of binocular difference of retinal illuminance on fusion, we used neutral density filter from 0.1 ND to 4.0 ND. While neutral density filter values were increased, we measured the least size fusion slide by major amblyoscope as well as the best corrected visual acuity. RESULTS: The best corrected visual acuity and the level of fusion were decreased significantly when monocular retinal illuminance was reduced to 2.0 ND (P<0.01, P<0.01, respectively). Although the visual acuity and fusion were equally influenced by retinal illuminance, the effect on fusion was more prominent when retinal illuminance decreased greatly. CONCLUSIONS: These results will be of help for the prevention and early detection of amblyopia, although further study will be needed in order to fully evaluate the influences of other factors on binocular fusion.

Key Words: Retinal illuminance;Visual acuity;Fusion;Neutral density filter