Diseases of the eye are a common medical condition. Vision slowly changes when people age. Aging is associated with serious eye diseases such as cataracts, diabetic retinopathy, glaucoma, and macular degeneration. These eye diseases can significantly impair a person's vision, cause blindness, and/or interfere with the activities of daily living. These eye diseases are relatively common and have an effect on vision and the ability of a patient to perform self-care. A basic understanding of common eye diseases and how they affect vision, as well as an overview of how to assist someone with impaired vision are discussed.