Abstract
Cataract is a typical age-related eye disease. As a cataract progresses, the crystalline lens becomes hazier and visual ability deteriorates. Since the main cause of visual impairment is light scattered by the hazy lens, both brighter environments and hazier lenses worsen visual ability. By focusing this characteristic, we developed two novel methods to estimate the haze factor of crystalline lens through simple visual tasks. In the first method, visual acuity is measured as the amount of scattering light is increased. In the second method, the illuminance of disability surround light is set by an observer. A higher haze factor is estimated with larger deterioration in visual acuity (from the 1st method) or with low illuminance level of disability surround light (from the 2nd method). These estimations of lens' haze factor are expected to serve as easy methods for assessing the progress of a cataract.
