About Vision Loss | Blind & Visually Impaired Center of Monterey County, Inc.

Low Vision

Low vision is a partial loss of sight (also referred to as partially sighted or visually impaired). It is often a loss of visual acuity or sharpness, but may also 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

Legal blindness is a level of visual impairment that has been defined by law to determine eligibility for benefits. The term Legally Blind identifies an individual whose central visual acuity is 20/200 or poorer in the eye with better vision when wearing best correction.

Legally Blind also applies to those individuals that may see better than 20/200 but have a limitation of their peripheral vision. Limitation of peripheral vision may be defined as a visual field diameter of 20 degrees or less in the eye with the larger visual field or a mean deviation of -22dB or greater in the eye with the better visual field.

The Four Most Common Causes of Vision Loss

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1) Age-Related Macular Degeneration (AMD)

Age-Related Macular Degeneration (AMD) is the leading cause of irreversible 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 does not cause total blindness.

2) Glaucoma

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.

3) Diabetic Retinopathy

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.

4) Cataract

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.

Projected Estimates of Vision Impairment

According to a study released in May 2016, Visual Impairment and Blindness in Adults in the United States will double by 2050. (Source: University of Southern California (USC) Roski Eye Institute).

“A study published by researchers at the University of Southern California (USC) Roski Eye Institute in JAMA Ophthalmology found that the US prevalence in visual impairment (VI) and blindness is expected to double over the next 35 years. By 2050, the number of Americans with a variety of eye disease and impairment issues, including age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR) and cataracts, will dramatically increase impacting both individuals and society, according to a USC news release.