Most commonly, vision loss among older people is due to clouding of the lens of the eye ( cataracts Cataract A cataract is a clouding (opacity) of the lens of the eye that causes a progressive, painless loss of vision. Vision may be blurred, contrast may be lost, and halos may be visible around lights... read more ) or to damage to the optic nerve (as occurs in glaucoma Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage (often, but not always, associated with increased eye pressure) that can lead to irreversible loss of vision... read more ) or the retina (as occurs in age-related macular degeneration Age-Related Macular Degeneration (AMD or ARMD) Age-related macular degeneration (AMD) causes progressive damage to the macula, the central and most vital area of the retina, resulting in gradual loss of central vision. Central vision becomes... read more and diabetic retinopathy Diabetic Retinopathy Diabetic retinopathy is damage to the retina (the transparent, light-sensitive structure at the back of the eye) as a result of diabetes. Blood vessels in the retina can leak blood and fluid... read more ). A less common cause of vision loss is blockage of the blood supply to the eye. Eyelid disorders mostly change the appearance of the eye and do not usually cause vision loss, but they can cause discomfort. Severe drooping of the eyelids can also interfere with vision.

Whatever the reason for vision loss, any vision change can compromise an older person's quality of life and, indirectly, health. For example, poor eyesight may contribute to a car crash or to a fall. Loss of vision can be especially devastating to older people coping with other problems as well, such as poor balance and hearing loss. In such cases, vision loss can contribute to significant injury and can impair a person's ability to do daily activities.