The development of the eye starts from birth and does not fully reach maturity until about age nine. If the eye for some reason is not properly used then the vision does not develop in that eye even though it is physiologically and structurally normal. This condition is called amblyopia. It may be associated with a turned in or lazy eye, known as strabismus, or due to a problem in the way the eye bends light, known as refractive error. One of the causes of amblyopia is a lazy eye or strabismus. In these conditions an eye may be turned in or turned out. In a normal eye the images from each eye are united to form a single image by the brain. In a person with a lazy eye the brain receives two different images which are not able to be united and this causes double vision. In order to overcome the annoying double vision the brain ignores or suppresses the image from one of the eyes. The eye in which the images are being suppressed does not have a chance to develop properly and this leads to the loss of vision known as amblyopia. A similar situation can occur if there is a problem with the bending of light rays in the eye known as a refractive error. If this is not caught early the image from one eye may be so blurry that the brain also suppresses images from that eye.

Unfortunately amblyopia may be difficult to detect in a young child particularly if the eyes are relatively straight. The child may not be aware with both eyes open that he is having trouble seeing out of one eye. There is no discomfort, redness or irritation to warn the child or the parent of a problem.

The treatment of this problem is best done at a very early age. The earlier the age the easier it is to reverse the amblyopia or loss of vision. If the cause of the amblyopia is due to a refractive or optical condition then glasses will be prescribed. If the eyes are turned in or turned out in some cases surgery will be required to straighten the eyes. The amblyopia particularly at a younger age responds very well to patching of the good eye forcing the unused eye to develop properly. In many patients the vision can be restored to near perfect vision.

The ideal age for a child to have their eyes examined is age four where these problems can be caught at an early age and intervention is highly effective.