Overview

Lazy eye (amblyopia) is reduced vision in one eye caused by abnormal visual development early in life. The weaker eye - or lazy eye - often wanders inward or outward.

Amblyopia typically develops from birth to 7 years of age. It is the leading cause of decreased vision among children. Rarely, lazy eye affects both eyes.

Early diagnosis and treatment can help prevent long-term vision problems in your child. The eye with poor vision can often be corrected with glasses or contact lenses, or patching therapy.

Symptoms

Lazy eye develops due to abnormal visual experience early in life that disrupts the nerve pathways between the thin layer of tissue (retina) at the back of the eye and the brain. The weaker eye receives fewer visual signals. Eventually, the eyes' ability to work together diminishes, and the brain suppresses or ignores input from the weaker eye.

Anything that blurs a child's vision or causes the eyes to cross or turn outward can result in lazy eye. Common causes of the condition include:

Deprivation. A problem with one eye—such as a cloudy area in the lens (cataract)—can impair clear vision in that eye. Deprivation amblyopia in infancy requires urgent treatment to prevent permanent vision loss. It is often the most severe type of amblyopia.

Risk factors

Complications

Treatment

Doctors may recommend glasses or contact lenses (for nearsighted or farsighted children) or surgery (for children with cataracts).

The next step is to retrain the brain and force it to use the weaker eye. The more the brain uses it, the stronger it becomes. Treatments include:

Wearing an eye patch on the stronger eye. By covering this eye with an eye patch (similar to a Band-Aid), the brain needs to use the weaker eye for vision. Some children only need to wear the patch for 2 hours a day, while others may need to wear it whenever they are awake.

Putting special eye drops in the stronger eye. A daily drop of the drug atropine can temporarily blur near vision, which forces the brain to use the other eye. For some children, this treatment works as well as an eye patch, and some parents find it easier to use (e.g., because young children may try to remove the eye patch).

Once your child starts treatment, their vision may begin to improve within a few weeks. However, it will likely take months to achieve the best results. After that, your child may still need to use these treatments from time to time to prevent amblyopia from recurring.

It's important to start treating children with amblyopia early—the earlier, the better. Children who go untreated may have vision problems throughout their lives. Treatment for amblyopia is generally less effective in adults than in children.