Amblyopia is an optic issue in which one eye tends to wander. Also called lazy eye, amblyopia tends to develop in early childhood and responds best to treatment performed before adolescence; different treatment methods may be more or less effective. Here’s a look at the causes of amblyopia.
Strabismic Amblyopia
Strabismus is similar to amblyopia in that one eye tends to wander in a different direction. This might be up, down, left, or right, while lazy eye is generally only on the horizontal plane. Characterized by an inability of the eyes to line up, strabismus is generally caused by an imbalance of the six intraocular muscles, which allow the eyeballs to move. When the eyes can’t move in tandem the brain tends to focus on the stronger eye, forgetting about the other so that vision tends to degrade.
Refractive Amblyopia
Refractive errors, such as being myopic (nearsighted, or unable to see far away), hyperopic (farsighted, or unable to see up close), having astigmatism, or different prescriptions for each eye are not uncommon. In some cases, however, the vision of each eye can be wildly different, making one eye significantly weaker than the other. This can contribute to amblyopia, causing refractive anisometropia. Then the brain starts to ignore the weaker eye and it becomes even weaker, eventually resulting in amblyopia.
Deprivation Amblyopia
Congenital (present from birth) cataracts are another common cause of lazy eye. Anything that prevents light entering the eye from birth can cause amblyopia. Much like the problem that results from refractive errors, the brain begins to ignore the eye that cannot see well. If issues such as infantile cataracts are not treated promptly, normal visual development will likely be interrupted, potentially causing issues far beyond a lazy eye.
Risk Factors
Most commonly, lazy eye develops as a result of strabismus in tandem with a refractive error. Whatever the cause, it interrupts the normal development of the nerves connecting the eyes and the visual center of the brain. While the causes of amblyopia are fairly clear, why those issues develop may not be quite so obvious, but certain risk factors can increase the chances of one (or more) of these problems developing. Genetics can play a role; a child from a family with a history of amblyopia is more likely to develop it in turn. Birth factors, such as being born prematurely or very small can also impact the likelihood of a lazy eye. Certain developmental disabilities may also increase the chances of amblyopia. If you suspect your child has a lazy eye, talk to an eye doctor as soon as possible to improve the efficaciousness of treatment options.
