Amblyopia | |
---|---|
Other names | Lazy eye[1] |
A child wearing an adhesive eyepatch to correct amblyopia | |
Pronunciation | |
Specialty | Ophthalmology, optometry |
Symptoms | Decreased vision |
Usual onset | Before age five[2] |
Causes | Poor alignment of the eyes, eye being irregularly shaped such that focusing is difficult, one eye being more nearsighted or farsighted, clouding of the lens[1] |
Diagnostic method | Vision testing[1] |
Differential diagnosis | Brainstem disorders, optic nerve disorder, eye diseases[3] |
Treatment | Glasses, eyepatch[1][2][4] |
Frequency | ~2% of adults[5] |
Amblyopia, also called lazy eye, is a disorder of sight in which the brain fails to fully process input from one eye and over time favors the other eye.[1] It results in decreased vision in an eye that typically appears normal in other aspects.[1] Amblyopia is the most common cause of decreased vision in a single eye among children and younger adults.[1]
The cause of amblyopia can be any condition that interferes with focusing during early childhood.[1][6] This can occur from poor alignment of the eyes (strabismic), an eye being irregularly shaped such that focusing is difficult, one eye being more nearsighted or farsighted than the other (refractive), or clouding of the lens of an eye (deprivational).[1] After the underlying cause is addressed, vision is not restored right away, as the mechanism also involves the brain.[6][7] Amblyopia can be difficult to detect, so vision testing is recommended for all children around the ages of four to five.[2]
Early detection improves treatment success.[2] Glasses may be all the treatment needed for some children.[2][4] If this is not sufficient, treatments which encourage or force the child to use the weaker eye are used.[1] This is done by either using a patch or putting atropine in the stronger eye.[1][8] Without treatment, amblyopia typically persists.[1] Treatment in adulthood is usually much less effective.[1]
Amblyopia begins by the age of five.[2] In adults, the disorder is estimated to affect 1–5% of the population.[5] While treatment improves vision, it does not typically restore it to normal in the affected eye.[2] Amblyopia was first described in the 1600s.[9] The condition may make people ineligible to be pilots or police officers.[2] The word amblyopia is from Greek ἀμβλύς amblys, meaning "blunt", and ὤψ ōps, meaning "sight".[10]
Putting special eye drops in the stronger eye. A once-a-day drop of the drug atropine can temporarily blur near vision, which forces the brain to use the other eye. For some kids, this treatment works as well as an eye patch, and some parents find it easier to use (for example, because young children may try to pull off eye patches).