Amblyopia: Causes, Diagnosis, and Treatment

Amblyopia, also known as lazy eye, is a condition in which the brain ignores one eye's input. This can happen for a variety of reasons, including strabismus (crossed eyes), refractive errors (nearsightedness, farsightedness, or astigmatism), or cataracts. Amblyopia is most common in children, but it can also occur in adults.

Causes of amblyopia

The most common cause of amblyopia is strabismus, which is a condition in which the eyes do not point in the same direction. When one eye is turned inward (esotropia), outward (exotropia), or upward (hypertropia), the brain may ignore the input from that eye in order to keep the images from the two eyes from conflicting.

Refractive errors, such as nearsightedness, farsightedness, or astigmatism, can also cause amblyopia. When one eye has a refractive error that is not corrected with glasses or contact lenses, the brain may ignore the input from that eye because it is blurry.

Cataracts, which are cloudy areas in the lens of the eye, can also cause amblyopia. When a cataract is present in one eye, the image from that eye may be blurry or distorted.

Symptoms of amblyopia

The most common symptom of amblyopia is blurred vision in one eye. Other symptoms may include:

• One eye may appear to be turned inward, outward, or upward.
• One eye may be smaller than the other.
• One eye may be red or irritated.
• One eye may be sensitive to light.

Diagnosis of amblyopia

Amblyopia is typically diagnosed by an eye doctor during a routine eye exam. The eye doctor will check the alignment of the eyes, the refractive error of the eyes, and the vision in each eye.

Treatment of amblyopia

The goal of treatment for amblyopia is to get the brain to use the input from the weaker eye. Treatment typically involves patching the stronger eye or using eye drops to blur the vision in the stronger eye. This forces the brain to use the input from the weaker eye.

Treatment for amblyopia is most effective in children under the age of 7. The earlier treatment is started, the better the chances of improving vision.

Patching

Patching is the most common treatment for amblyopia. The stronger eye is patched for several hours a day, usually 2 to 6 hours a day. The patch is worn for a period of time, typically 6 to 12 months.

Eye drops

Eye drops that blur the vision in the stronger eye can also be used to treat amblyopia. The drops are typically used for 2 to 6 hours a day, usually for a period of 6 to 12 months.

Vision therapy

Vision therapy may also be used to treat amblyopia. Vision therapy involves exercises that help the brain to use the input from the weaker eye. Vision therapy may be used in addition to patching or eye drops.

Prognosis for amblyopia

The prognosis for amblyopia is good if it is diagnosed and treated early. In most cases, treatment can improve vision to near normal. However, if treatment is delayed, the chances of improving vision are reduced.

Prevention of amblyopia

There is no sure way to prevent amblyopia, but early detection and treatment are important. Parents should take their children to an eye doctor for regular eye exams, starting at the age of 6 months.