Part of growing older involves adapting to physical changes that affect your mobility and perception. Changes in eyesight are common and you may find focusing on close work, such as reading or sewing, difficult. Many older adults expect to need reading glasses to magnify small print, and this change is age related. Other changes that impair vision, however, are not a normal part of aging and may cause permanent vision loss.
Definition
Low vision includes a variety of degrees of visual impairment, from blind spots to blurred vision to near total vision loss, according to the Cleveland Clinic. The strict definition describes low vision as visual acuity of 20/70 or worse that cannot be corrected with glasses or contact lenses, states the University of Michigan Kellogg Eye Center. A person with 20/70 vision can see at 20 feet what a person with perfect eyesight can see at 70 feet. Vision loss can occur at any age, but particularly in people older than 75 years.
Symptoms
Symptoms of low vision include difficulty seeing signs or other distant objects clearly, the inability to differentiate colors and trouble seeing near objects, for example, reading, notes the Kellogg Center. These signs may not necessarily indicate you have uncorrectable low vision, but you should consult your eye care provider if you experience any of these symptoms.
Causes
Low vision in the elderly is typically caused by the effects of general medical conditions on the eye, such as diabetes, or by diseases specific to the eye, explains the Low Vision Center website. Diabetes may cause a condition called diabetic retinopathy, in which capillaries in the retina leak, swelling the retina and blurring vision. Vision loss caused by diabetic retinopathy usually consists of blurred or spotty vision. Macular degeneration is also a common cause of low vision. The macula, which is the central portion of the retina that perceives fine detail, either becomes dry and thins, or leaking capillaries cause it to thicken and become uneven. In either case, the macula no longer functions properly, causing a loss of peripheral vision and blurring central vision. Cataracts commonly occur in elderly people. A cataract is a clouding of the lens of the eye, resulting in blurred or hazy vision. Glaucoma is caused by increased pressure within the eyeball that may damage the optic nerve. As glaucoma progresses, the field of vision narrows.
Treatment
Treatment for low vision is limited. In some cases, the underlying condition may be treated and vision restored or improved. Visual impairment caused by diabetic retinopathy, for example, can be improved or restored by treating the diabetes, notes the Low Vision Center. Cataracts require surgical replacement of the damaged lens. Low vision caused by other factors, however, is permanent.
Coping
The Cleveland Clinic describes several types of devices that help people cope with low vision. Magnifying glasses, reading prisms and light-filtering lenses help improve eyesight. Clocks and telephones with large numbers and high-contrast dials enable those with impaired vision to remain self-sufficient. Large-print reading materials and software that reads text are other tools to cope with low vision. Occupational therapy teaches coping skills and offers suggestions for home modifications to improve mobility and safety for elderly people with poor eyesight.
