Hesperian Health Guides
Causes of Blindness
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Different people have different beliefs about what causes blindness. In some parts of the world, people think a child is born blind as punishment for something the parents have done. In parts of Latin America, villagers believe that a bat’s urine fell in the baby’s eyes, or that a ‘black witch moth’ flew by the baby’s face. These things do not really cause blindness, and as people get new information, many are leaving these older beliefs behind.
We now know that child blindness is usually caused by poor nutrition or infection, and that most blindness in children can be prevented.
COMMON CAUSES OF BLINDNESS IN CHILDREN ARE:
|SIGNS OF XEROPHTHALMIA|
|First sign may be night blindness. Child sees worse than others in the dark.|
|Next the eyes look ‘dry’. The white part loses its shine, begins to wrinkle, and forms patches of little gray bubbles (Bitot’s spots).|
|Later, the dark part (cornea) also gets dry and dull, with little pits.|
|Finally, the cornea may get soft, bulge, or burst, causing blindness.|
|FOODS THAT HELP PREVENT IT|
|1. ‘Dry eyes’ (xerophthalmia, or nutritional blindness) is the most common cause of child blindness. It is especially common in parts of Africa and Asia. It results when a child does not get enough vitamin A, which occurs naturally in many fruits and vegetables (and also in milk, meats, and eggs). ‘Dry eyes’ develops in children who are not regularly fed any of these foods. It often appears or quickly gets worse when these children get diarrhea or have measles, whooping cough, or tuberculosis. It is much more common in children who are not breast-fed.|
Dry eyes can be prevented by feeding children foods with vitamin A. Encourage families to grow and eat things like papaya, squash, carrots, and leafy green vegetables in a family garden. Be sure the child eats these foods regularly, beginning at 6 months old.
Vitamin A capsules or liquid can also prevent dry eyes, but should not take the place of a well-balanced diet. Give 200,000 units (60 mg. retinol) once every 4 to 6 months (or 100,000 units to babies less than 1 year old). Do not give this large dose more often than 4 to 6 months, because too much vitamin A can poison the child. For treatment, give 200,000 units (I.U.) of vitamin A at once, 200,000 I.U. the next day, and 200,000 I.U. 2 weeks later. Give half the dose to children under age 1. See a health worker.
|2. Trachoma is the commonest cause of preventable blindness in the world. It often begins in children and may last for months or years. If not treated early, it can cause blindness. It is spread by touch or flies and is most common in poor, crowded living conditions.|
Trachoma can often be prevented by keeping the child’s eyes clean and keeping flies away. To prevent blindness from trachoma, treat early with erythromycin or tetracycline eye ointment (see a health worker, or Where There Is No Doctor, p. 220).
|SIGNS OF TRACHOMA|
|Begins like ‘red eye’ with red, watery, sore eyes. Or in children it may develop for months with few or no early signs.|
|After a month or more, small lumps form inside the upper eyelids.|
|White of the eye becomes inflamed or swollen|
|Top edge of the cornea may look cloudy.|
|After years the lumps inside eyelids begin to go away, leaving whitish scars.|
|The scars may pull the eyelashes down into the eye, scratching the cornea and leading to blindness.|
|3. Gonorrhea or chlamydia in the eyes of newborn babies causes blindness if not treated immediately. The eyes get red, swell, and have a lot of pus. Blindness can be prevented by putting erythromycin or tetracycline eye ointment, or 1 drop of povidone-iodine solution, in the eyes of all babies at birth. The mother can pass these infections to her baby at birth even if she has no signs of infection.|
|If the baby’s eyes get red, swell, and have a lot of pus in them within the first month, he may have one or both of these infections. If you cannot test to find out which disease is causing the infection, give the baby medicines for both.||Put the ointment inside the lower lid.|
|Treatment for gonorrhea: inject 125 mg. of ceftriaxone in the thigh muscle, 1 time only.|
Treatment for chlamydia: give 30 to 50 mg erythromycin syrup by mouth, 3 times a day, for 14 days.
|If a baby develops gonorrhea or chlamydia of the eyes, both parents must be treated for these infections too. See Where There Is No Doctor (pages 236, 237 and 360) or Where Women Have No Doctor.|
|4. River blindness (onchocerciasis) This disease of the eyes and skin is becoming less common. It is still found in parts of Africa, Yemen, and a few communities in the Amazon region of South America. River blindness is caused by tiny worms that are carried by black flies. The worms get inside a person when an infected fly bites him.
The illness can lead to eye problems and sometimes blindness. First there may be redness and watery eyes, then signs of iritis may follow. Where ivermectin is given every 6 months or once a year as part of community-wide campaigns, fewer people get the disease and it may disappear from the region.
|5. Measles, which can injure the surface of the eyes, is a common cause of blindness, especially in Africa and in children who are poorly nourished.|
|6. Brain damage causes blindness in many children, usually in combination with cerebral palsy or other disabilities. Brain damage can happen before, during, or after birth. Causes include German measles during pregnancy, delayed breathing at birth, and meningitis.|
|7. Eye injuries often cause blindness in children. Pointed tools, fireworks, acid, lye, and homemade bombs to dynamite fish are common causes.||WARNING!|
Running with a pointed object is DANGEROUS TO THE EYES.
|8. Also, blindness in children is sometimes caused by other problems such as hydrocephalus, arthritis, leprosy, brain tumors, or certain medicines. Cataracts (clouding of the lens inside the eye) gradually develop in about half of older children with Down syndrome.|