Visual impairment is a loss of vision that cannot be restored with eyeglasses, contact lenses, medicine, or surgery. It can occur at all ages, but the most common causes of this condition are diseases that appear later in one's life and that are primarily age-related. These diseases include glaucoma, macular degeneration, and cataracts. Other eye disorders, inherited conditions, accidents, and injuries can also be causes of visual impairment.
Age related macular degeneration most often appears in individuals 60 years of age and older, and is one of several common causes of visual impairment. It causes cells in the macula to die. The macula is the area in the eye responsible for fine and clear vision, which is necessary for activities like reading or driving. The disease may progress slowly or quickly, depending on the individual. Onset can be detected through regular eye exams, and treatment can be prescribed to help delay the progress of the disease.
Cataracts are also an age-related cause of visual impairment. Vision becomes blurred due to cloudiness of the lens, resulting in double vision and glare in addition to blurriness. Cataracts progress slowly and can be corrected with special glasses but surgery is very common. During surgery, the affected lens is replaced with an artificial lens. Preventive measures may be taken by protecting the eyes from sunlight with sunglasses or hats.
Glaucoma, a condition in which the optic nerve is damaged by high fluid pressure inside the eyes is often age-related. It can usually be detected with a complete eye exam. Treatment to prevent glaucoma-related blindness consist of applying liquid drops to the eyes or, in some extreme cases, having surgery performed.
Other common causes of visual impairment are diabetes and high blood pressure. Eye injuries, infections, and tumors can also impair vision as can stroke, high cholesterol, vitamin A deficiency, and human immunodeficiency virus. Infections that are passed on from mothers to their infants can cause congenital blindness, a problem primarily in developing countries in which the mother may not have access to proper medical care.
Regular eye exams, cessation of smoking and treatment for diabetes or other chronic diseases can help prevent these common causes of visual impairment or help to slow the onset of age-related eye diseases. Protecting the eyes from sunlight or other ultraviolet exposure, even during common activities, such as working outside, also helps prevent eye injuries and the accompanying partial or complete vision loss.