What is Lazy Eye?
Strabismus and amblyopia are visual conditions that are often referred to as ‘lazy eye’. Both of these conditions alter communication between the eye and the mind.
Strabismus is commonly known as crossed or wall-eyed and refers to any form of misalignment between the two eyes. One eye is used for fixation on a target while the other eye drifts off into another direction. When one eye drifts away from the other, double vision can occur. With increased frequency a second condition can develop in which suppression of vision occurs. This means that the brain begins to tune out the visual input from the misaligned eye. Over time suppression can lead to decreased central visual clarity (amblyopia) as the eye is stimulated less and less.
Strabismus can be constant or intermittent – and therefore not always observable to the untrained eye. Disorganization and loss of depth perception follows as the brain struggles to make sense of unorganized visual input.
Amblyopia refers to decreased visual signals travelling from the eye to the brain. This can occur in one or both eyes and may or may not be associated with strabismus. Amblyopia typically develops in order to minimize neural disorganization and confusion. Suppression of central visual pathways can vary from mild to moderate degrees. With prolonged suppression visual clarity becomes poor and is often untreatable with glasses or surgery.
While strabismus is often noticeable to many people, amblyopia is not. Amblyopia is one of the leading causes of vision loss in children aged birth to five years of age. The only way to detect amblyopia is with a comprehensive vision evaluation. Most people do not realize the importance of visual care for infants and toddlers. The regular well-baby check-ups performed by pediatricians will not detect amblyopia. The only way to identify if your child has amblyopia is with a thorough vision evaluation by your optometrist. The fact that your child may not be able to talk and respond to tests is not important. The tests used to evaluate infants and toddlers are very different from tests used for older children and adults. The sad part is that many times amblyopia is left undetected for several years in very young infants and toddlers. This results in severe vision loss and often is not detected until the child enters school. Treatment at this stage is still possible but will likely need to be more extensive then if the problem was detected at an earlier age.
Strabismus and amblyopia always require professional attention. These types of problems will rarely go away if left untreated. Surgery may cosmetically straighten the eyes in cases of strabismus, but it usually does not improve visual function without pre- and post-vision therapy. Vision therapy is necessary to teach the eyes how to work together as a team with equal degrees of intensity from both the right and left eyes.
Adults can also benefit from treatment and therapy to improve decreased visual function.