The aging eye undergoes a variety of structural and physiologic changes that can impair vision and cause functional disability. Among the changes are backward displacement of the eye into the orbit, thickening and yellowing of the lens, decrease in pupil size, increase in laxity of the lids, and accumulation of waste products in the retina. The specific diseases of the eye that occur with aging include macular degeneration, cataracts, glaucoma, diabetic retinopathy, and sudden vision loss. Preventive care both in old age and earlier in life may help forestall ocular changes and the subsequent morbidity and mortality they cause. Environmental changes to accommodate visual change can be important in accident prevention and in improved functioning and quality of life.