Causes of Blindness

Normal Vision

Normal vision

Objects have clear contrast, with vivid colors and details.

Hemianopia Example


Hemianopia can result in vision loss in half of the field as a result of a defect in the optic pathways in the brain. Hemianopias leave half of the reading field blacked out.

Glaucoma Example


Glaucoma is caused by elevated eye pressure which causes optic nerve atrophy. It is usually detected by pressure checks and routine eye examinations. In advanced cases, images may appear faded and side vision may be lost. Print appears to lack contrast.

Cataract Example


Cataract do not affect field of vision but give general hazy vision especially in glaring light.

Diabetic Retinophathy Example

Diabetic Retinophathy

Diabetic Retinophathy is caused by retinal changes in advanced or long term diabetes. It may affect the macula or the entire retina and vitreous. Reading is variable, and print may be distorted or blurred. Many diabetics also develop cataracts resulting in hazy and distorted vision.

Age related Macular Degeneration Example

Age-related Macular Degeneration

Age-related macular degeneration affects the central portion of vision but not the side vision. It is difficult to see faces and print may be distorted or have missing segments of words.

Retinitis Pigmentosa Example

Retinitis Pigmentosa

Retinitis Pigmentosa is a heredity disease causing degeneration of the pigmented layer of the retina. It leads to severe loss of peripheral vision causing problems with travel. Reading area is reduced although some letters in the center may be clear.

See it for yourself

Vision Simulator apps allow anyone to “view” different vision problems on their smart phone or tablet.

All image credit National Eye Institute (NEI)