Amblyopia or “lazy eye” is reduced vision in one or both eyes, even while wearing the best corrective glasses, and not due directly to any structural abnormality of the eye itself. It is caused by an abnormal experience of vision in one or both eyes at a very young age, typically from birth to age 9, with younger onset being more severe. Anything which causes the eye(s) of a young child or infant to get a distorted view of the world can cause amblyopia, by interrupting how the young visual brain and eye(s) are learning how to work together and develop. It usually affects central vision.
Amblyopia can be:
Refractive: caused by the image being blurry because the eye is out of focus due to myopia (nearsightedness), hyperopia (farsightedness), or astigmatism (a curvature of the cornea or lens which distorts image).
Strabismic: caused by any misalignment of the eyes, in which one eye is crossed, drifting outwards, going up, or down.
Deprivational: caused by anything which blocks the entrance of proper light into the eye, like ptosis (droopy eyelid), a cataract (cloudy internal lens), tumors or abnormalities of the optic nerve or retina.
Amblyopia is treatable when diagnosed properly at a young age by a skilled pediatric eye care professional. Pediatric practices have implemented sophisticated automatic screening techniques to be able to predict which children are at risk for developing amblyopia. These children are then referred for a fully dilated, medical exam of the eyes to look for amblyopia or its risk factors. Family history of early childhood glasses (before age 6), patching therapy, and eye muscle surgery, is an important risk factor for amblyopia, and children of these families should have a thorough eye exam before the age of 2.
Treatment of amblyopia includes correcting for the root cause primarily with glasses, which may be prescribed at any age, including for affected infants. Sometimes, surgery of the muscles, eyelids, or the lens, is needed. Patching of the stronger eye with an eye patch, or blurring of the stronger eye with a special eye drop (Atropine 1%), is often necessary to help strengthen the vision of an amblyopic eye. Amblyopia treatment can go on for many years, until the child is 9, and requires frequent medical check ups (every 2-6 months, depending on severity and age) in order to be effective.