By Shoichi Ayukawa, Hiroyuki Shinoda and Yasuhiro Seya
Cataract is one of the most typical age-related eye diseases. As the cataract progresses, the crystalline lens becomes hazier and such lens causes light scattering within the eye, resulting in decreases in the visual ability such as color vision and spatial resolution. In this study, we measured spatial resolution for pseudo-cataract young subjects wearing foggy filters. Subjects observed a grating through an integrating hemisphere inside which LEDs (inducing further scattering as glare) were attached. We manipulated the light intensity from LEDs (i.e., level of glare) and the haze factor of the filter. The results showed that, irrespective of the haze factor, the spatial resolution decreased as the level of glare increased. However, the rate of the decrease changed with the haze factor; it was larger as the haze factor increased. From the analyses of spatial resolution obtained, we propose a new method for estimating the haze of the crystalline lens.