About Refractive Amblyopia

Amblyopia is also known as "lazy eye," and can take many forms. With refractive amblyopia, one eye consistently has blurred vision. This condition is often missed by optometrists.

Identification

• Amblyopia results from problems in the visual system. As a result, one eye has poor or otherwise diminished vision, though it is otherwise normal (or at least has less structural abnormalities than the vision problems would indicate). Approximately 1 to 5 percent of the population is afflicted with amblyopia.

Misconceptions

• The term "lazy eye" is the colloquial way of referring to amblyopia, but the term is inaccurate, because there is no actual laziness involved. The condition is caused by either no or severely limited transmission of visual information from the eye to the brain for an extended period of time. This can be due to a period of eye trouble or arise early in childhood. Normally, only one eye will develop amblyopia, though it is possible for both eyes to be afflicted.

Features

• Amblyopia is a problem related to the brain, not the eye (although structural abnormalities in the eye that prevent the transmission of visual information can create amblyopia). When there is a lack of information sent to the brain, that part of the brain does not develop properly due to lack of stimulation. This theory has been confirmed by direct examination of the brain.

Types

• Refractive amblyopia can result from a condition known as anisometropia, which is a difference in the refractive indices between two eyes. What this means is that the two eyes have widely differing levels of strength and clarity in looking at images. The eye that has the best vision will become dominant, and the weaker eye will transmit blurred vision, causing developmental problems in the corresponding part of the brain. This type of amblyopia is milder and is often missed by physicians, because there is no obvious physical symptom that can be observed.

Prevention/Solution

• All types of amblyopia are more easily treated if detected early, which gives the affected portion of the brain a better environment for catching up. The best way to correct refractive amblyopia is by correcting the weaker eye, along with either putting a patch or some other penalizing agent over the good eye. When using this form of treatment, however, it is important not to over-penalize the good eye, as this can cause the balance to swing the other way, giving the formerly strong eye amblyopia.