Healthcare at West Virginia University

Babies are able to see as soon as they are born. For vision to continue to develop properly, children need clear input from both eyes to the brain. If there is a problem that interferes with vision in either eye or both, the connections from the eye to the brain can become weak or not develop properly. Crossed or turned eyes or imbalance in the way each eye focuses can interfere with normal vision development.

Children should have their vision checked by a pediatrician, family doctor, or an ophthalmologist by age three or sooner (age six months to a year) if there is a family history of vision problems. A doctor will refer your child to a specialist in ophthalmology if they see any sign of amblyopia, difficulty in measuring vision, or if they suspect an abnormality of the alignment or structure of the eyes. Ophthalmologists can perform a complete eye exam on children of any age.

Your child's eye examination begins with the doctor asking you if you’ve noticed any vision problems. Were there problems with the pregnancy or with your child's birth? Are growth and development proceeding normally? Is there a history of eye problems in the family? Are there other medical problems? Is your child on any medications or have allergies? Has your child had surgery?

If your child has been treated with medications, glasses, or contact lenses, these should be brought to the eye examination. The names and addresses of other doctors who may be treating your child should be supplied so we can inform them of the findings.

Four percent of children have eye problems that can diminish vision in one or both eyes. The three most common types of problems that occur are strabismus, amblyopia, and refractive errors (focusing problems).

Strabismus is a general term referring to eyes that point in different directions. After four months of age, all infants should have straight eyes. One eye may drift in or out, up or down. A crossed eye is known as esotropia. Exotropia refers to eyes that are turned out. Strabismus may be present all of the time or intermittently. Children with strabismus are usually unaware of the problem. Strabismus interferes with developing coordinated use of both eyes together.

Amblyopia, which is sometimes called "lazy eye," refers to developing poor vision in one or both eyes. It occurs in infancy and early childhood during the sensitive period of visual development. The earlier amblyopia is detected, the easier it is to treat.

Many parents are quite surprised to find that a complete eye exam can be performed on their baby. A skilled ophthalmologist can get a good idea of how well children can see based on the way they use their eyes to look at and follow attractive toys and lights.

No matter how vision is tested, it is important to check each eye separately. Two to 5 percent of children have 1 eye that does not see as well as the other.

For older children who can talk, but do not yet know their numbers or the alphabet, the doctor uses special charts that have pictures common in their world, such as birds, birthday cakes, and stars.

Some tests may require your child to point to a letter that matches a letter on a chart. All of these tests show smaller and smaller items in order to get an idea of your child's best visual ability.

Testing for binocular vision (the ability to use both eyes together) and depth perception can also be done early in childhood.

In some situations, evaluations may be made of your child's vision based on brain wave measurements while he or she watches striped patterns or looks at black and white stripes on flash cards.

The doctor uses lights to see if the pupils are working properly. During this portion of the exam, the areas around the eyes, such as the eyelids and the tear canals, are also examined.

A flashlight can also be used to see if your child's eyes are straight or turned. This is important in infants because their wide noses may make their straight eyes look crossed. Sometimes, the doctor will cover one eye and then the other. If the eyes are not aligned properly, they will jump back and forth when looking at the light or a toy. Wedge-shaped pieces of clear plastic called prisms can be used to measure the amount of misalignment of the eyes.

One of the less enjoyable but essential portions of an eye exam is dilating the pupils. This procedure not only allows the doctor to view the inside of the eye, but the dilating drops temporarily relax the child's focusing power so that nearsightedness, farsightedness, or astigmatism can be measured. Some drops are given once, some are given more than once, and all take about 30 to 60 minutes to be fully effective. It may be necessary to have special drops or ointment put in at home and to return to complete the examination later.

The doctor shines a beam of light into the eye and, by holding lenses in the path of this reflection, can detect nearsightedness, farsightedness, or astigmatism. From this part of the examination, we can determine if your child needs glasses.

Once your child's pupils are dilated, the doctor uses special instruments to get a good look at the structures inside the eye. The inside of the eye is where the retina is located, which is like film in a camera. The retina processes visual information into signals that are sent via the optic nerve to the brain. The optic nerve itself, as well as the blood vessels that supply the retina, can be seen in the back of the eye.