When someone has amblyopia there may not be an obvious problem with the eye. This is because vision loss occurs along nerve pathways between the brain and the eye. Due to this lack of stimulation, the brain learns to favor one eye typically due to poor vision in the other eye. Amblyopia of often referred to as lazy eye, and is the leading cause of vision loss among children.
Individuals with amblyopia have decreased depth perception, and have difficulty seeing 3-D images. Parents often times say that their child is clumsy, has a tendency to stumble or bump into objects.
There are several types of amblyopia:
- strabismic amblyopia
- deprivation amblyopia
- efractive amblyopia
The types of amblyopia have different causes:
- Strabismic amblyopia develops when the eyes are not straight. One eye may turn in, out, up, or down. As a result, the brain begins to ignore or turn-off that eye. When this happens vision in that eye declines.
- Deprivation amblyopia develops when there is a cataract or similar condition that deprives the eye of visual stimulation or experiences.
- Refractive amblyopia develops when there is a large, or unequal, amount of refractive error (glasses prescription) between the two eyes. The brain learns to see through the eye that has a lesser need for glasses and learns to ignore the other eye.
It is not easy to readily recognize amblyopia, especially deprivation or refractive amblyopia. Unless the child has an eye-turn it is difficult for parents to know something is wrong.
How is amblyopia detected? Amblyopia is detected by finding the difference in visual acuity between the two eyes. Poor vision in one eye does not always mean a child has amblyopia. An eye doctor trained in pediatrics is the best choice for detecting amblyopia. The eye doctor will dilate your child's eyes to determine if any other eye diseases may be affecting your child's vision.
Early diagnosis and treatment is important, and increases the chance for complete recovery. An individual does not “out grow” amblyopia, nor does amblyopia go away on its own. If amblyopia is not diagnosed for several years or until the individual is an adult, treatment takes longer and in some cases may be less effective.
What is the treatment for amblyopia?
Treatment for amblyopia can include a combination of prescription lenses, prism, atropine drops, patching and vision therapy. If strabismus is the cause of amblyopia and treatment with glasses, patches or drops, or vision therapy do not fully correct the alignment of the eyes, surgery may be an option.
- Prescription glasses are used to provide clearer vision so the brain receives clearer, focused images which will teach the brain to “pay attention to” or “switch on” the weaker eye. This allows the brain to begin using the eyes together and normal vision to develop.
- Patching, or atropine drops, is used to make the amblyopic eye (the weaker eye) work to recognize images. When vision in the stronger eye is blocked by a patch, or blurred by the use of atropine drops, it forces the brain to recognize images seen by the weaker eye.
- Vision therapy teaches the two eyes to work together, which helps prevent amblyopia from reoccurring.
- Surgery may be an option is strabismus is the cause of amblyopia and treatment with glasses, patches or drops, or vision therapy do not fully correct the alignment of the eyes. Surgery may also be considered if amblyopia is caused by a cataract.
How common is amblyopia?
Amblyopia is the most common cause of vision impairment or vision loss among children. Amblyopia affects approximately 2 to 3 out of every 100 children, making amblyopia more common than most people think. If you suspect that your child has amblyopia, schedule an appointment with a binocular vision specialist. Accurate diagnosis, early intervention and proper treatment can change a child's life.