Amblyopia, more commonly called "lazy eye", refers to poor vision in an eye as a result of improper visual development during infancy and childhood. In rare cases it can be a result of toxic reaction to a drug or substance ingested. It is a relatively common condition affecting approximately four percent of the population.
There are a number of reasons why an eye may develop amblyopia. The most common cause is a misalignment of the eyes because of muscle problems. Other causes include significant differences in focusing between the two eyes, high amounts of astigmatism, and disorders such as cataracts. If the brain were to pay attention to both eyes, double vision would result. The brain then suppresses or "switches off" the vision in one of the eyes to avoid this. Subsequently, vision never develops in the visual cortex of the brain that corresponds to that eye. So, amblyopia is not really a problem with the eye, but rather the brain--in essence a learning disability.
In most of these cases, the person will become dependent on the one good eye.
It is important that an experienced eye care professional examine the eyes of any infant or child suspected of poor vision or having a "lazy eye". There are a number of tests that will be used to determine eye health including how well objects are followed, how well the eye muscles work, and if glasses are required. Therefore, all children should have an eye exam by age three.
Early detection of amblyopia is vital because treatment is only effective in the very early years. After approximately eight to nine years of age, the beneficial results of therapy drop significantly, since the brain is less capable of rewiring itself after this age.
Treatment is dependent on the cause and the degree of the amblyopia along with the patient's age. The most common form of treatment is patching the strong eye every day for a couple hours, while the child is doing an activity he likes, such as playing video games or watching TV. Treatment often takes weeks or months. Forcing the poor eye to see helps to develop and strengthen the vision for that eye.
This can be very difficult for a young child; therefore, the parent or caregiver has to be very supportive and involved in the therapy. The child's progress must be closely monitored by an eye doctor.
Successful treatment depends greatly on the severity of the condition and how early it is diagnosed. With early detection, most amblyopic children gain improved vision, although continued treatment may be needed until the child reaches age nine or so.
Parents and other caregivers are the key to successful treatment. While obtaining the cooperation of a young child is not easy, it is the supportive involvement of the child's family coupled with early professional intervention that should most likely produce a successful outcome.