Five Leading Causes of Visual Impairments in Children in the USA
- Cortical Visual Impairment: “Cortical visual impairment (CVI) is a neurological disorder, which results in unique visual responses to people, educational materials, and to the environment. When students with these visual/behavioral characteristics are shown to have loss of acuity or judged by their performance to be visually impaired, they are considered to have CVI.” For more in–depth information and definitions go to www.aph.org/cvi/define
- Retinopathy of Prematurity: “Retinopathy of Prematurity (ROP) is an eye disorder affecting premature infants. This disorder was called Retrolental Fibroplasia in the past. ROP affects immature blood vessels of the retina. It occurs weeks after birth. Once development of blood vessels is complete, a child is no longer a candidate for this disorder.” www.blindbabies.org/factsheet_rop.htm
- Optic Nerve Hypoplasia: “Optic Nerve Hypoplasia (ONH) refers to the underdevelopment of the optic nerve during pregnancy. The dying back of optic nerve fibers as the child develops in utero is a natural process, and ONH may be an exaggeration of that process. ONH may occur infrequently in one eye (unilateral) but more commonly in both eyes (bilateral). ONH is not progressive, is not inherited, and cannot be cured. ONH is one of the three most common causes of visual impairment in children.” www.blindbabies.org/factsheet_onh.htm
- Albinism: “Albinism refers to a group of inherited conditions. People with albinism have absent or reduced pigment in their eyes, skin or hair. They have inherited genes that do not make the usual amounts of a pigment called melanin which is essential for the full development of the retina. Lack of melanin in development of the retina is the primary cause of visual impairment in albinism. In the USA it is estimated that one person in 17,000 has some type of albinism.” www.albinism.org or www.blindbabies.org/factsheet_albinism.htm
- Optic Nerve Atrophy: “Optic Nerve Atrophy (ONA) is a permanent visual impairment caused by damage to the optic nerve. The optic nerve functions like a cable carrying information from the eye to be processed by the brain. The optic nerve is comprised of over a million small nerve fibers (axons). When some of these nerve fibers are damaged through disease, the brain doesn’t receive complete vision information and sight becomes blurred. Atrophy (wasting away) may be partial in which some axons are damaged or profound in which most axons are damaged. A child’s ability to see clearly (visual acuity) is affected due to nerve damage that occurs in the central part of the retina responsible for detail and color vision (macula). These areas of the eye are more vulnerable to the effects of atrophy. ONA is the end result of damage to the optic nerve. It can affect one or both eyes. It may also be progressive, depending on the cause.” www.blindbabies.org/factsheet_ona.htm