| Low vision is a term commonly used among eye | | | | iris, ciliary body, lens, retina, choroid or optic nerve. |
| care professionals to mean partial sight, or sight | | | | - Glaucoma. Glaucoma is a condition resulting from |
| that isn't fully correctable with surgery, | | | | an increase of pressure inside the eye, often |
| pharmaceuticals, contact lenses or glasses. Low | | | | from improper drainage of fluids, which can cause |
| vision can result from a variety of diseases, | | | | damage to eye structures such as the optic |
| disorders, and injuries that affect the eye. Low | | | | nerve. |
| vision can also be caused by heredity. Many | | | | - Macular degeneration. Macular degeneration |
| people with low vision have age-related macular | | | | involves the gradual loss of sensitivity of the |
| degeneration, cataracts, glaucoma, or diabetic | | | | central portion of the retina. Since this is the area |
| retinopathy. Age-related macular degeneration | | | | of the retina responsible for detail vision, macular |
| accounts for almost 45 percent of all cases of | | | | degeneration is often associated with the loss of |
| low vision. | | | | central vision and the ability to see fine detail. |
| Following are some of the most common causes | | | | - Nystagmus. Nystagmus is the involuntary |
| of low vision: | | | | movement of the eyes resulting in the inability to |
| - Albinism. Albinism results from a lack of pigment. | | | | maintain a steady fixation. The movement can be |
| Some forms of albinism affect only the eyes | | | | horizontal, vertical, circular, or mixed. |
| (ocular) while other forms affect skin and hair | | | | - Optic atrophy. Optic atrophy is the degeneration |
| color as well as the eyes (oculocutaneous). | | | | of the optic nerve. Loss of function of the optic |
| Albinism is hereditary. | | | | nerve results in a decreased ability to transmit |
| - Aniridia. Aniridia is the partial or total absence of | | | | electrical signals to the visual center of the brain. |
| the iris of the eye. The lack of an iris results in | | | | - Optic nerve hypoplasia. This is a condition in |
| acuity loss, light sensitivity and visual field loss. | | | | which the number of nerves within the optic |
| - Aphakia. Aphakia is the absence of the lens of | | | | nerve bundle is reduced. |
| the eye which prevents the ability to adjust focus | | | | - Retinitis pigmentosa. This is a progressive |
| between objects at different distances. | | | | degeneration of the retina resulting in night |
| - Cataracts. Cataracts result from the lens of the | | | | blindness and peripheral field loss. |
| eye becoming cloudy or opaque. The clouding can | | | | - Retinopathy of prematurity. This is a condition in |
| occur over the entire lens or over a small area | | | | which the normal growth of blood vessels in the |
| over the lens. Surgical removal of the cataract | | | | retina is disturbed during fetal development, often |
| can result in aphakia. | | | | due to circumstances surrounding premature birth. |
| - Coloboma. Coloboma is a birth defect occurring | | | | This condition can lead to an increased risk of |
| during the development of the fetus resulting in | | | | retinal tears or retinal detachment. |
| an underdevelopment, such as a cleft in the pupil, | | | | |