The University of Arizona

The Tohono O'odham
Vision Screening Program

The University of Arizona

Common Vision Problems for Tohono O'odham Children

What kind of vision problems do Tohono O’odham children have? Many Tohono O’odham children, and children of other Native American tribes, have an eye condition called astigmatism. Approximately one in every three Tohono O’odham children (33%) requires glasses for astigmatism, and children with astigmatism usually have astigmatism in both eyes. We do not know why so many Tohono O’odham children have astigmatism. However, we do know that if children do not get glasses for astigmatism when they are young (before age 8), they can develop a condition called amblyopia.

What is astigmatism?   Astigmatism is a condition in which the front of the eye (the cornea) is more steeply curved in one direction than another. Instead of the front surface of the eye being round and equally curved in all directions like a basketball, it is shaped more like a football or an egg: it is curved more in one direction than in the other direction.

Astigmatism Image
Astigmatism Image

People with astigmatism do not see clearly at any distance – up close or far away – when they are not wearing eyeglasses. Because of the shape of the front of the eye, their eyes can not bring images into focus. If children with astigmatism do not wear glasses when they are young, they can develop a condition called amblyopia.

Amblyopia is poor vision that cannot be corrected with eyeglasses. People with amblyopia do not have perfect vision, even when they are wearing their eyeglasses. For the visual part of the brain to develop correctly, young children need to see clearly: The eye needs to be able to bring images of what the child is looking at into focus. If the images are not focused clearly, the visual part of the brain does not develop the way it should. Children with astigmatism who do not wear glasses while their vision is still developing can develop amblyopia.

What can we do to assure that the children do not develop amblyopia?   The treatment for amblyopia is wearing glasses. If children with astigmatism get eyeglasses when they are young, and wear them, there is a good chance that they will not develop amblyopia. For older children who did not have glasses when they were young, it is possible that they have developed amblyopia and that the glasses will not help them gain perfect vision. However, even these older children should see better with their glasses on than with their glasses off.

Sometimes it is difficult to get children to wear glasses. Getting used to glasses that correct astigmatism can take a week or two. However, we have found that if parents and teachers work together to encourage the children to wear their glasses, the children will eventually become used to wearing them.

Once a child has been prescribed eyeglasses, he or she should receive regular eye examinations every 12 months. The eye doctor can make sure that the child’s prescription is still correct, and can check to see if the child’s eyeglasses are in need of repair or replacement.

Sponsored by
The Tohono O’odham Nation
The University of Arizona
The National Eye Institute of the National Institutes of Health