Suspecting a vision problem with your child? Our experts make the most common conditions crystal clear.
Many kids see with 20/20 vision, but a significant number have what is medically known as a refractive error. That's because in order for our eyes to see, light rays are bent, or refracted, by our eye's cornea, lens, and tear film so they can reach back to our retina, which is a layer of light-sensitive cells lining the back of the eye. When light rays form a picture, the retina sends that image to the brain through the optic nerve. But tiny changes or errors in the shape of our eye can alter how those light rays reach the retina -- and how clearly we can see that picture. There are three types of such errors:
Nearsightedness (myopia) means a child can see objects clearly close up, but has trouble seeing distances (like the classroom blackboard). This happens when the eye is longer than normal or has a cornea (the clear window at the front of the eye) that is too steep, so light rays focus only in the front of the retina. Myopia is most commonly diagnosed in children between the ages of 8 and 12. It usually gets worse during the teenage years, but stabilizes between ages 20 and 30.
Farsightedness (hyperopia) means words on a page will seem blurry, but distances are not as much of a problem. This happens when the eye is shorter than normal so light from close objects cannot focus clearly on the retina. Hyperopia is particularly common in young children, but they may not notice any blurriness because their eyes can compensate by focusing.
Astigmatism distorts or blurs vision for both near and far objects -- it's like looking in a funhouse mirror and it happens when the cornea is shaped more like a football than like a round, smooth basketball. Myopia and hyperopia can be combined with astigmatism, or astigmatism can happen on its own. Astigmatism in infants goes away in many cases but can last into adulthood.
Four percent of preschoolers are nearsighted, 21 percent are farsighted, and 10 percent have astigmatism, according to a National Institutes of Health study of almost 10,000 children aged 6 months to 6 years old.
What Causes Refractive Errors?
Humans are born with pretty imperfect vision, and normally it is due to the immaturity of the brain. "But most babies don't need glasses," says Jane Edmond, M.D., a pediatric neuro-ophthalmologist at Texas Children's Hospital and Baylor College of Medicine and clinical spokesperson for the American Academy of Ophthalmology. "In spite of their eyes having some refractive error, they will usually develop normal vision without specs. Initially, babies only see nearby objects clearly. Their vision improves as they get older and they start seeing objects well around a year of age, as their brain and retinas mature," Dr. Edmond says. But if you or your husband wear glasses, it is possible that your kids will need glasses, too (and maybe at around the same age as you were when you got your first pair). Refractive errors that require correction are mostly inherited, but there are a lot of environmental issues that can have an effect that are not well understood.
Your health during pregnancy can play a pivotal role in your child's eye health, Dr. Edmond says. "Good prenatal care, good nutrition, and no smoking can do a lot to prevent eye problems." In fact, children of mothers who smoked during pregnancy had a 1.5 times greater risk for a refractive error (farsightedness or astigmatism), according to a National Institutes of Health study of almost 10,000 children aged 6 months to 6 years old.
What Treatments Are Available?
If your child's refractive errors are moderate to severe, she may need to be fitted for glasses. "But not all refractive errors need to be corrected," Dr. Edmond says. In fact, it's normal for babies to be farsighted with astigmatism because they don't develop distance vision until they are about 1 year old. By age 3, a child's vision should be at least 20/40 and by age 5, at 20/30. Even if your child's prescription is higher, the ophthalmologist may hold off on glasses to encourage his natural focusing mechanism to correct the error. But if a refractive error is severe, causes a child to have trouble in school, or persists past the age of 8, glasses will usually be recommended.
Let your pediatrician know if your baby is not tracking and following objects by 4 months of age, or recognizing you from across the room between 6 and 9 months. "A baby may need glasses if she seems visually inattentive compared to other babies her age or if she holds a toy abnormally close to her face," Dr. Edmond says. If vision development appears to be on track, a child will have her first vision screening in the pediatrician's office around age 3; if that screening shows that her prescription is 20/40 or worse, she should see an ophthalmologist for a full eye exam.
When to Worry: Eye and Vision Problems
Copyright © 2014 Meredith Corporation.
All content on this Web site, including medical opinion and any other health-related information, is for informational purposes only and should not be considered to be a specific diagnosis or treatment plan for any individual situation. Use of this site and the information contained herein does not create a doctor-patient relationship. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.