Amblyopia, also known as lazy eye, is an eye disorder in which one eye's neural functioning is weaker than the other, causing visual disturbances. The condition originates in the brain, not the eye, and usually manifests in childhood affecting about one in twenty-five children in the UK.
Amblyopia can result from genetics and a hereditary condition known as strabismus – in which the eyes are misaligned – is an associated cause. Sometimes referred to as being ‘cross-eyed’, there are different degrees of severity and strabismus is not always present with Amblyopia. In Amblyopia the neural pathway from the brain to the eye in one eye is underdeveloped in childhood. As a result visual imagery can appear blurry or distorted and lack definite detail. Other eye conditions, such as astigmatism in one eye, cataracts and being near or farsighted can also cause lazy eye.
Lazy eye presents visual distortion symptoms such as difficulty judging distances or depth, a sense that the eyes are functioning separately, misalignment of the eyes and irregular visual experiences. Someone with Amblyopia may experience difficulties seeing, reading and may also have eyestrain which causes tiredness. A sense of confusion may be felt in trying to comprehend visual information.
Ocular or eye examinations by an ophthalmologist and orthoptist are used to diagnose visual disorders, such as lazy eye. In the UK the vision of children is tested in schools for early treatment to stop and prevent the development of eye disorders. A paediatrician may also refer a child for ocular tests if Amblyopia is suspected.
The condition is treatable once diagnosed during a full eye examination. The treatment type depends on the severity of Amblyopia and if other eye conditions are also present, such as cataracts, strabismus, astigmatism and refractive disorders. Amblyopia can be quite easily treated by training the Amblyopic eye to function better. Such training includes:
Other treatments for eye disorders may include:
If not treated in childhood, adults can suffer visual loss that may or may not be corrected through treatments or laser surgery. By the time the neural pathways are fully developed the condition is harder to reverse.
Early intervention and treatment by age five will enable quicker and healthier recovery, enabling the Amblyopic eye to begin to function normally. Not having treatment can result in permanent eye damage and visual loss, which may require surgery. In some cases the visual loss may not be recovered.
If caught early in childhood treatment can be provided to improve eye function, so that vision returns close to normal.