Information about Vision Loss and the Major Causes
Low vision is a partial loss of sight (also referred to as partially sighted, severe vision impairment). It is often a loss of visual acuity or sharpness, but may be a loss of side vision or extreme difficulty with light or glare. Low vision exists when functional vision cannot be adequately corrected with eyeglasses, contact lenses, medications or surgery.
Legal blindness is a level of visual impairment that has been defined by law to determine eligibility for benefits. It refers to a central visual acuity of 20/200 or less in the better eye with the best possible correction, as measured on a Snellen vision chart, or a visual field of 20 degrees or less.
SightConnection provides specialized vision rehabilitation programs and services in King, Snohomish and Skagit counties with the purpose of equipping individuals with the skills necessary to maintain independent lifestyles.
The Four Most Common Causes of Vision Loss
Age-Related Macular Degeneration (AMD) is the leading cause of irreversible severe central vision loss in Caucasians over the age of 50 in the U.S. The incidence and progression of all the features of AMD is known to increase significantly with age. It results from damage to the macula, which is the central part of the retina responsible for central vision and ability to see detail. Although the extent of central vision loss can be significant, macular degeneration alone rarely causes total blindness. View our Macular Degeneration information sheet for more information.
Glaucoma in its most common form is the second leading cause of blindness in the United States, and the leading cause of blindness among African-Americans. Glaucoma is a disease where pressure within the eye is so high that it can damage the optic nerve and lead to vision loss. It affects side vision long before central vision is affected. Although glaucoma cannot yet be prevented, it can usually be controlled or stopped with treatment and medication. View our Glaucoma information sheet for more information.
Diabetic Retinopathy is a complication of diabetes caused by damage to blood vessels in the retina. It is one of the four leading causes of severe vision impairment in older Americans. The risk of developing diabetic retinopathy is greater the longer someone has diabetes. According to the American Academy of Ophthalmology, about 80 percent of people who have had diabetes for at least 15 years have some damage to the retina. For more information view our Diabetes and Diabetic Retinopathy information sheets.
Cataract is a clouding of the lens of the eye, which is normally clear. Light can no longer pass through the lens easily, and vision becomes hazy or blurred. The current treatment, which is safe and highly successful, is surgical removal of the lens which is usually replaced with an intraocular man-made lens.
There are many other conditions that can cause a significant loss of vision. It always best to consult with your eye care physician about any concerns with your vision and to get regular eye exams.
Our Public Information Series provides information on SightConnection services, adaptive devices, techniques and common eye health issues for individuals and family members.
Age Related Eye Diseases At A Glance provides an overview of some of the major eye conditions.
Projected Estimates of Vision Impairment
According to Prevent Blindness America, twice as many people will be blind in 2030 as there are today (Prevent Blindness America, 1998-2000). The following projections are based on estimates of self-reported vision impairment from The Lighthouse National Survey on Vision Loss (The Lighthouse Inc., 1995) and applied to U.S. Census population projections.
- 17% of persons age 45 and older report some form of vision impairment, representing 16.5 million persons. By the year 2010, when all baby boomers are age 45 and older, this number will increase to 20 million.
- 9% of persons age 45 and older report severe vision impairment, representing 8.7 million persons. By the year 2010, when all baby boomers are age 45 and older, this number will increase to 10.7 million.
- About 7.3 million, or 21% of persons age 65 and over, report some form of vision impairment. As baby boomers age, this number will reach 8.3 million in the year 2010; 11.3 million in 2020; and in 2030, 14.8 million persons age 65 and older will report some form of vision loss.
- About 3.8 million or 11% of persons age 65 and over, report severe vision impairment. As baby boomers age, this number will reach 4.3 million in the year 2010; 5.9 million in 2020; and in 2030, 7.7 million persons age 65 and older will report a severe vision impairment.
(Sources: Prevent Blindness America 1998-2000 and The Lighthouse Inc., 2005)