Lazy Eye (Amblyopia)

What is Lazy Eye?

Lazy eye (Amblyopia) is a disorder of sight that occurs when the eye and the brain are not working well together. Lazy eye is a condition in which the child’s eyesight doesn’t develop properly. In most cases the problem affects only one eye but sometimes the condition can affect both eyes. Lazy eye causes reduced vision in an eye that otherwise looks fine.

When a person has amblyopia the brain directs its attention to one eye and completely neglects the other eye (lazy eye). In the United States and England, Amblyopia affects 2% to 3% of all children and is the most common cause of partial or total blindness in one eye in the United States.

It’s important to note that the term lazy eye is inaccurate because the eye is not lazy. Lazy brain is actually a more accurate description of what lazy eye really is because lazy eye is due to improper brain development. Lazy eye could be caused by strabismus (misaligned eyes) and anisometropia (high degrees of nearsightedness, farsightedness, or astigmatism in one or both eyes).

What are the Symptoms of Lazy Eye?

Lazy eye may cause reductions in visual acuity, contrast sensitivity function, vernier acuity, spatial distortion, abnormal spatial interactions, and impaired contour detection. Individuals with Amblyopia may also suffer from binocular abnormalities such as impaired stereoacuity (stereoscopic acuity) and binocular summation which is a process by which the brain combines the information from both eyes.

Lazy Eye Causes

A lazy eye can be caused by a number of conditions. The most common cause is when one of the eyes is able to focus better than the other. One of the eyes may have a vision problem that the other doesn’t, such as astigmatism or farsightedness. In the child’s brain, there are two images coming from the eyes, one that is blurry and one that is clear. When this happens, the brain will ignore the blurry image and simply use the clear one. As this continues over time, this causes the vision in the poorer eye to get even worse.

In some cases, the child’s eye may not line up well. One of the eyes may turn outward or inward instead of being better aligned like the other eye. This can cause double vision from the images from both eyes coming in. This causes the brain to ignore the image coming from the misaligned eye. When that happens, the sight in the misaligned eye will get worse. This condition can also be related to being born prematurely and/or a small size. It can also be related to developmental disabilities, and it can appear in kids who have a family history of lazy eye.

How is Lazy Eye Treated?

Involves treating an underlying eye problem and getting the affected eye to work so that vision can develop. Eye glasses may be prescribed and cataracts may be surgically removed to improve the vision in the lazy eye. Some may use an eye patch over the good eye which may force the lazy eye to work and get better.

Lazy Eye Prevention

The only way to prevent a lazy eye before it begins is to have the child see an optometrist regularly to be screened for this condition. The treatment for this condition is more successful when it is caught quickly. Early treatment of a lazy eye also keeps the lazy eye from losing more of its vision than it already has. Once the condition has already begun, one common way to prevent it from getting worse is to patch the stronger eye so that the weaker eye must work harder in order to see. This can strengthen the weaker eye until it is as strong as the unaffected eye.