Amblyopia, also known as a “lazy eye”, is described as a reduced vision in one eye compared to the other. There are some rare forms of amblyopia that involve both eyes. Amblyopia is the most common cause of partial or total blindness in one eye in children.
The term lazy eye is misleading because the eye is not actually lazy. In fact, it is a developmental problem in the nerve connecting the eye to the brain, affecting the brain’s ability to use both eyes together. It is not a problem in the eye itself, but in the brain which actively ignores the visual input from the misaligned eye, leading to amblyopia in that eye.
In addition to poor visual acuity, people with amblyopia are more prone to having difficulties with depth perception, eye movements related to reading, and visual decision making while driving.
Amblyopia develops in childhood due to:
Significant differences in the prescription (refractive) status between the two eyes due to nearsightedness, farsightedness or astigmatism;
Constantly misaligned eyes or crossed eyes (strabismus);
An obstruction of vision in early childhood i.e. cataract, ptosis (droopy eyelid)
It is important to note that, because amblyopia is typically a problem of infant vision development, symptoms of the condition can be difficult to detect. Symptoms may include noticeably favoring one eye over the other, an eye turn (either upward-downward outward or inward) or a tendency to bump into objects on one side.
The best way to identify children who are at risk for or already have amblyopia is by performing comprehensive eye examinations.
Amblyopia can be treatable at any age, although the earlier the problem is found and treated, the more successful the outcomes tend to be.