Visual Impairment

Visual impairment, also known as vision impairment or vision loss, is a decreased ability to see to a degree that causes problems not fixable by usual means, such as glasses. Some also include those who have a decreased ability to see because they do not have access to glasses or contact lenses. Visual impairment is often defined as a best corrected visual acuity of worse than either 20/40 or 20/60. The term blindness is used for complete or nearly complete vision loss.

Causes

Visual impairment can be caused by a variety of factors, including disease, genetics, and injury. Some of the most common causes of visual impairment include age-related macular degeneration, glaucoma, cataract, and diabetic retinopathy. Other causes can include infections, inflammation, neurological disorders, and trauma.

Diagnosis

Diagnosis of visual impairment often involves a series of tests to measure visual acuity and field of vision. These tests may include a Snellen chart for distance vision, a Jaeger chart for near vision, and a perimetry test for peripheral vision. Other tests may be used to identify the specific cause of the visual impairment.

Treatment

Treatment for visual impairment depends on the underlying cause. In some cases, visual impairment can be corrected with glasses or contact lenses. In other cases, surgery may be required. For those with irreversible visual impairment, rehabilitation can help improve quality of life.

Epidemiology

Visual impairment is a significant global health issue. According to the World Health Organization, approximately 285 million people worldwide are visually impaired, of which 39 million are blind.

See also

• Blindness
• Low vision
• Visual perception

Visual Impairment Resources
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