Causes of Low Vision
Some of the most common visual impairments that can cause low vision include the following:
- Age-Related Macular Degeneration (AMD/ARMD): AMD is a leading cause of vision loss among Americans over age 60. It accounts for nearly half of all low vision cases. It is caused when the part of the eye responsible for sharp, straight-on vision – the macula – breaks down and causes a loss of central vision. There are two types of AMD, wet and dry. Wet AMD is caused by the growth of abnormal blood vessels under the macula. Central vision loss occurs rapidly with wet AMD. In dry AMD, light-sensitive cells in the macula slowly break down, leading to a gradual loss of central vision.
- Diabetic Retinopathy: According to the National Eye Institute, more than 30 percent of Americans diagnosed with diabetes have some form of diabetic retinopathy. It is a major cause of blindness and is directly related to high blood sugar, which damages blood vessels. That damage affects the retina and can even lead to its detachment.
- Glaucoma: Glaucoma is the second leading cause of blindness. With glaucoma, portions of vision are lost over time, usually with no warning signs or symptoms prior to vision deterioration. For many, a decrease in peripheral vision is the first sign of glaucoma.
- Cataracts: Over 20 million people in the US alone have cataracts according to Prevent Blindness America. It appears as a clouding of the lens of the eye.
- Retinitis Pigmentosa: This is a group of inherited diseases affecting the retina resulting in progressive vision loss. This type of vision impairment often begins in childhood with poor night vision and progresses over time.
There are also many additional causes of low vision, including strokes, TBI (traumatic brain injury) and other diseases common among a wider age range such as Stargardts, albinism, ROP (retinopathy of prematurity), among others.