Vision problems in children are uncommon. But when they do occur, they often go undetected. Young children may not realize or be able to communicate that their vision is impaired, and even older children may not notice if the vision in only one eye is affected. Every parent wants their child to have perfect vision, so how often should children have eye examinations to make sure their eyes are healthy?

 

Every newborn undergoes a brief eye examination shortly after birth, mainly to ensure that no birth defects of the eye are present. This is usually performed by a pediatrician, family physician, nurse practitioner, or a physician’s assistant. A similar examination should take place between six and twelve months of age, usually during a well-child check-up with a pediatrician or family physician. A primary goal of this second examination is to ensure that light can enter the eye unobstructed, so that vision will develop normally. This is evaluated by shining a light into the eye and observing a red or orange glow, called a red reflex, in the pupil of the eye—similar to the red eye often seen in photographs taken using a flash. Any problems that prevent light from entering the eye—such as extreme far-sightedness, crossed eyes, or even a cataract—can prevent normal vision development, a condition called amblyopia, or lazy eye.

 

Once a child reaches age 2 ½ to 3 ½, and certainly by the age of 5, a vision screening should take place to make sure that vision is developing normally. Children in this age group are preparing to enter pre-school or kindergarten, and this examination is a good check for school readiness. This examination can be done during a well-child visit to the pediatrician or family physician, but should include some measurement of the child’s vision. Most children this age cannot read the letters on the eye chart, but special vision-testing charts—including some with easy-to-recognize pictures—are available for children this age. Because vision is vulnerable to amblyopia in this age group, a formal examination by an eye care specialist should take place if the pediatrician is unable to perform testing, or if the test results are in any way abnormal. Some children in this age group have high degrees of near-sightedness or far-sightedness, and need glasses to help their vision develop normally.

 

If all of the examinations through age 5 are normal, it is not necessary to have any more routine screening eye examinations unless there are specific vision problems. Most children will undergo one or more vision screenings in elementary school, providing additional opportunities to identify vision problems. In some cases, these screenings may consist of a special photograph that can identify children who are near-sighted, far-sighted, or both, or who have misaligned eyes (called strabismus). All of these conditions can cause amblyopia, which can be treated if it is identified during the critical vision development period that lasts until children are about 10 years old. While it is not absolutely necessary, a routine eye examination should be considered in the mid-teens, to ensure that vision is adequate to begin driving.

Babies are not born with perfect vision. Normal vision develops slowly over the first several years of life. The eye and the brain together learn how to see over the first few years of life. And like a muscle, vision only grows if it is used. If for any reason the brain does not receive a clear image through an eye, that eye will never learn to see clearly. If sight does not develop normally, this is called amblyopia, or lazy eye.

 

Lazy eye can be caused by a number of common childhood eye conditions. If children are extremely near-sighted or far-sighted, both eyes will be constantly blurred and both may become lazy. Some children have one eye that is more near-sighted or far-sighted than the other, and can develop amblyopia in just the one eye.

 

Another common childhood eye condition that can cause lazy eye is ocular misalignment, also called strabismus. This is a condition in which the two eyes are looking in different directions. This may look like crossed eyes if the misaligned eye points inward, or wall eyes if the misaligned eye points outward. In either case, only one eye at a time is looking where the child wants to look, and to avoid double vision, the brain ignores the vision coming through the misaligned eye. If this vision is ignored long enough, lazy eye can develop in the misaligned eye.

 

Some uncommon causes of lazy eye are conditions that block vision from entering the eye, such as a droopy eyelid or a cataract. These are uncommon in children, but do happen to some children.

 

A lazy eye can be treated to restore normal vision. But it has to be diagnosed in order to be treated, and timing is very important. If a lazy eye is not diagnosed and treated by the age of 9 or 10, the vision loss becomes permanent. All children should have their vision measured before starting school and at least once or twice while in elementary school to make sure that their vision is developing normally in both eyes. Any abnormal vision measurement, whether in one or both eyes, should be evaluated by an eye specialist to make sure amblyopia is not present.

 

Treating lazy eye depends in part on the cause of the amblyopia, and the first step is to fix the cause. Droopy eyelids can be tucked, and cataracts can be removed. For more common causes, glasses can correct near-sightedness or far-sightedness, and eye muscle surgery can re-align misaligned eyes.

 

Once the cause of amblyopia is fixed, the vision lost must be regained. This is often accomplished by patching the good eye for brief periods, or blurring the vision in the good eye with special eye drops. Patching or blurring the good eye forces the lazy eye to work harder, so that vision in the lazy eye catches up to vision in the good eye. It is important to follow the doctor’s instructions carefully when blurring the good eye with a patch or eye drops, because too much blurring of the good eye can make it become lazy.