The optometrist says my mom has low vision. What does this mean?
The term low vision or visual impairment means that a person is not blind but is seeing below the normal level. At this level, a person still has useful vision even though they cannot be helped by surgery, medication, standard spectacles, contact lenses or laser surgery. It affects everyday tasks such as driving, working, reading the papers, shopping, cooking, watching TV, and writing. Low vision has a variety of causes, including eye injury, diseases and heredity. Sometimes low vision involves a lack of acuity, meaning objects are seen blurry instead of clear, it may involve the ability to distinguish colours, see contrasts or determine spatial relationships among objects, or it may affect your visual field – how wide an area you can see. It may be congenital – a condition you are born with, or it may be due to injury or disease. Although low vision can occur at any age, it occurs primarily in the elderly as a result of disease processes affecting the eyes. The primary diseases that contribute to low vision are macular degeneration, diabetic retinopathy, and glaucoma. Cataract, although it can decrease the vision and patients see blurry, is not defined as a cause of low vision, because the vision can be improved by cataract surgery. People with low vision usually retain some usable vision. Some visually impaired people become completely dependent on friends and relatives, while others suffer alone. An ophthalmologist or optometrist specializing in low vision can evaluate how you see and prescribe optical devices to maximize your remaining vision.
What kind of devices
are available?
Over 124 million people in the world have low vision and it is estimated that over 50% can be helped with low vision devices. Your optometrist will work with you to decide the best way to utilize your remaining vision. There are several devices available that can magnify the print images so that you may be able to read. These include magnifying glasses or stand magnifiers, spectacle mounted, bar or dome types and close circuit televisions (CCTVs), hi-tech computerized systems that increase print size on normal television screens. For distance vision, telescopes can be hand held or fitted in front of your spectacles.
If the cause of your low vision is macular degeneration, special filtres (coloured lenses) can improve contrast and improve vision. If the cause is diabetic retinopathy, your optometrist may refer you back to your family doctor so that you can get your blood sugar under tighter control and to an ophthalmologist for laser surgery. This is in an effort to slow down the damage of the blood vessels that cause the disease and make sure you do not lose more of your vision.
Is there
anything I can
do at home?
Yes, several things. These include buying large-print books and magazines. Readers Digest magazine comes in a large print edition as well as many books and cookbooks. There are telephones, watches and clocks with large numbers. Try to use black or navy lettering on white surfaces. You can get electronic ‘talking’ clocks, thermometers, blood pressure machines, and phones. Make sure you have bright and properly positioned lights for reading. Persons with low vision can still be productive and contribute to their communities.
