The eyes are responsible for receiving light and sending that information in the form of neurological signals to the brain. Problems in one eye can lead to amblyopia, also known as lazy eye. Amblyopia can be subtle but, if not treated in time, can result in the permanent loss of vision in one eye.
Symptoms
Amblyopia is most easily identified, according to the Mayo Clinic, by eyes that do not move together. Although amblyopia can affect both eyes, it generally only involves one eye. Amblyopia should not be confused with strabismus, which is marked by a large turn or deviation in one eye, also known as crossed eyes, Strabismus.org notes. Amblyopia involves one eye not coordinating its movements with the other eye. The affected eye may wander inward or outward and often has severely impaired vision.
Causes
Amblyopia is the result of the brain ignoring the neurological signals from one eye, generally due to some defect in one of the eyes. The most common cause of amblyopia, Medline Plus explains, is strabismus. Severely impaired vision in one eye, which can be in the form of near- or far-sightedness, can also cause amblyopia. Astigmatism and childhood cataracts can also lead to amblyopia. Any problem that causes the brain to primarily rely on one eye for vision can lead to amblyopia if it occurs before the age of 10.
Diagnosis
Although severe cases of amblyopia can be obvious to most people, more subtle forms of this disease often go undiagnosed, according to Strabismus.org. Amblyopia generally is diagnosed with a thorough eye exam, which typically involves visual acuity charts that are more in-depth than the commonly used 20/20 vision charts with rows of letters. Amblyopia commonly is suspected, however, in patients with a vast difference in vision between eyes.
Treatment
The main treatment for amblyopia, according to the National Eye Institute, involves forcing a patient's brain to process visual signals from the weaker eye. This can be done using special atropine eye drops, which can be placed in the stronger eye. These atropine drops cause temporary blurring in the stronger eye, forcing the brain to use the other eye for visual input. Amblyopia can also be treated by placing a patch over the stronger eye, again forcing the brain to rely on the other eye for visual stimulation.
Complications
The most dangerous complication of amblyopia is permanent blindness in one eye. The visual portions of the brain develop early in life and typically stop developing by the age of 10. As a result, if amblyopia is not treated by the time the patient's visual center stops developing, the amblyopia will be permanent and cannot be corrected.
