Visual Impairment as a Public Health Problem in 2021

Eighty percent of all visual impairment can be prevented or cured by considering the two leading causes of visual impairment in the world, i.e., uncorrected refractive error and cataract. Cataracts cause vision loss owing to clouding of the lens, with age being the greatest risk factor. Cataract surgery can greatly improve vision and is highly effective. It is the most commonly performed surgery in developed countries. Uncorrected refractive error can be resolved simply by wearing proper eyeglasses or contact lenses. Although traditionally considered a problem in developing countries, uncorrected refractive error is now known to be more common among older people in developed countries. Glaucoma is the most important cause of visual impairment in Japan, accounting for 29% of all cases. Compared with other eye diseases of the visually impaired population, glaucoma is the only one that has been increasing both in number and percentage.