Does My Child Have a Lazy Eye?
“Lazy Eye” is a common term that refers to an eye that is not working properly. The eye may turn in or wander out (or up) and not line up correctly with the other eye, as if it were being lazy. Other people use the term “lazy eye” for an eye that does not see as well as the other eye. The American Association of Pediatric Ophthalmology and Strabismus (AAPOS) can help parents understand how specialists identify poor vision in the eye of an infant or young child.
Amblyopia (one of the kinds of lazy eye) is a condition in which the brain connections for vision are better in one eye than the other. This common condition affects one out of every 45 children. In the past, amblyopia was often not detected until age 5 or 6 when a child had their vision checked in school by covering each eye and reading letters or recognizing pictures. Unfortunately, by then the child was usually too old to treat amblyopia and improve vision, which causes parents to feel guilty because they overlooked a treatable condition in which one of their child’s eyes is now legally blind.
Some children have one eye that is “in focus” and one that is “out of focus.” This abnormality is a result of uncorrected farsightedness (hyperopia), nearsightedness (myopia) or astigmatism in one eye. When a child has normal vision in one eye, their outward behavior may fail to indicate a vision problem exists; therefore, it is very uncommon for parents to pick up the severe loss of vision in the lazy eye or to suspect a problem.
When an infant or child has one eye that is way out of focus, the brain will establish more connections to the better seeing eye and fewer connections to the out of focus eye, resulting in even further loss of vision. Sometimes the out of focus eye begins to drift in or out and parents will notice this misalignment and have the child seen by a specialist. Frequently, the out of focus eye remains in alignment with the better eye, such that the parent or pediatrician has no way to suspect a problem in one eye. A specialist, such as a pediatric ophthalmologist, trained to examine infants and very young children, will be able to detect and treat the problem.
A pediatric ophthalmologist is an Eye MD (an eye physician and surgeon) who specializes in children. A pediatric ophthalmologist graduated from medical school and completed a three or four-year approved ophthalmology residency program training in all aspects of eye disease. In addition, this type of physician received further training in an approved fellowship program dedicated to the study of eye diseases and disorders of children’s eyes such as hyperopia, myopia, astigmatism, strabismus and amblyopia. Pediatric ophthalmologists who are members of AAPOS have demonstrated high qualifications in the proper treatment and care of children’s eyes.
There are several ways that commonly detect amblyopia in young children. These tests include picture chart vision, photorefraction and a complete eye exam. By age 3, most children can be tested at home with a picture chart or home vision test. Prevent Blindness, located at www.preventblindness.org/children/distance_child.html on the Internet, provides both the picture chart and home vision test for parents. The picture chart test has the advantage of being an actual assessment of the ability of the child to see with each eye; however, many young children are not cooperative enough for the test. Others are so eager to please their parents or the examiner that they cheat by peeking with the good eye or even memorize the chart. It is very important to perform such a screening exam carefully, because many children with amblyopia have “passed” the test in this manner without detection of their eye problem.
A second technique used to help detect a difference in vision of the eyes of young children is called photoscreening or photorefraction. Both techniques use high-tech, hand held devices that shine a light into the eyes. The returning reflection must be analyzed. These instruments often require skilled interpretation by a technician or physician to decide if one or both eyes are out of focus. While these devices are still being modified, they may be of value in the early detection of visual problems requiring a thorough examination by a pediatric ophthalmologist.
Parents can opt for a complete eye exam for their child from the beginning, especially if there is a family history of eye problems. The optimal time for the first exam may vary. For example, premature infants may require an eye exam at age 4 to 6 weeks to detect possible change in the retina (the blood vessels in the back of the eye). A family history of an eye disease beginning in early childhood, such as cataracts or retinoblastoma (the most common malignant eye tumor in children) calls for an eye exam in the first two months of life or immediately if a white pupil is noted. Children with a family history of amblyopia or eye muscle problems should have an eye exam between 6 and 12 months of age.
The best time for a complete eye exam for a child with both eyes lined up and appearing to see normally and no family history of early eye problems is between 3 and 4 years of age. A child does NOT have to be able to read a picture chart in order to have a complete eye exam. Pediatric ophthalmologists have many other ways to detect problems in the eyes of infants and children.
An eye exam for children with no vision problems may seem like an unnecessary expense, but once vision is lost to amblyopia, sight can, in most cases, only be restored during a critical period in early childhood - usually birth to about age 4 - the most important years in visual development.
For more information, visit the AAPOS Web site at http://med-aapos.bu.edu or call the AAPOS at (415) 561-8505.
