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.

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.

produce distorted or cloudy vision with greater glare sensitivity. Like cataracts, field of vision is normal. Print appears to lack contrast.

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.

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.

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

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.