Blindness in children is primarily caused by vitamin A deficiency, congenital cataracts, and retinopathy of prematurity (ROP). Leber congenital amaurosis, a rare genetic disorder, is also a cause of blindness in children. These health issues, coupled with physical injuries, cause the majority of vision problems in youngsters, an issue affecting over 1.4 million children worldwide.
Vitamin A deficiency accounts for nearly 70% of cases of blindness in children. Most often occurring in developing countries, this type of malnutrition can cause night blindness and full-fledged blindness. Vitamin A is needed by the retina in the eye for it to absorb light. The absorption of light through the retina is essential to the development and maintenance of sight.
Congenital cataracts cause at least 16% of childhood blindness. Cataracts present from birth can result in low vision or vision loss and are typically caused by an infection during pregnancy, Alport syndrome, and Fabry disease. A cataract, or clouding of the lens of the eye, is treatable if caught in time by removing the cataract and, in severe cases, placing an artificial intraocular lens. This routine surgery often resolves the disorder, although some children are left at least partially blind.
Prior to 32 weeks gestation, the blood vessels in the retina are not fully formed. These vessels typically grow from the back of the eye to the front, beginning at 16 weeks gestation and ending a little before 40 weeks, which is the point when a fetus is considered full term. When a child is born prior to 32 weeks or less than 3.3 pounds (1.4 kilograms) the growth of these vessels rapidly slows or in some cases stops completely. This health issue, known as ROP, resolves itself in approximately 85% of cases. In the other 15%, however, the vessels of the eye can become deformed, causing partial or full blindness in children.
Leber congenital amaurosis (LCA) is a rare type of genetic eye disease that is apparent before birth or shortly afterward. Affecting one in 80,000, LCA is the result of two copies of a gene mutation known as an autosomal recessive disorder. Other than blindness in children, LCA can cause extreme sensitivity to light, abnormally deep set eyes and random eye movements.
Physical injury to the eyes is also a common cause of blindness in children, especially during the toddler years. Getting sprayed in the face with harsh chemicals, lacerations of the eyes, or other physical harm can cause irreparable damage to a child's sight. Blindness in children, while sometimes preventable and often treatable, is a serious medical issue. With proper nutrition and early newborn eyesight screenings, many children have been able to recover a large portion of their sight.