Amblyopia, also called lazy eye, is a disorder of sight due to the eye and brain not working well together. It results in decreased vision in an eye that otherwise appears normal. It is the most common cause of decreased vision in a single eye among children and younger adults.
The cause of amblyopia can be any condition that interferes with focusing during early childhood development. Amblyopia is NOT a droopy eyelid. however, a droopy eyelid can cause amblyopia only if the lid droops low enough to cover the pupil of one eye.
This can occur from poor alignment of the eyes(eyes crossing or turning out one eye being more nearsighted or farsighted or having more astigmatism than the other, or clouding of the lens of an eye (cataract) or even a droopy eyelid that covers the pupil during the time that the brain is developing. After the underlying cause is fixed, vision is not restored right away, because the part of the brain associated with that eye has not developed properly Amblyopia can be difficult to detect, so vision testing is recommended for all children before the ages of four to five
Early detection improves treatment success. Eye glasses may be the only treatment needed for some children. If this is not sufficient, treatments which force the child to use the weaker eye are used. This is done by either using a patch or putting dilating drops in the better eye. Without treatment, amblyopia typically persists into adulthood. Evidence regarding treatments for adults is poor.