Lazy Eye; Amblyopia & Strabismus

The term “Lazy Eye” is often confused. Many people understand lazy eye to mean an eye that turns in or out. The medical term for that is Strabismus. Amblyopia, which is different, means that the “wiring” between the eye and the brain was not developed and therefore visual information is not being procesed by the brain.

These two can be present at the same time. They can also occur separately. Someone can have:

esoStrabismus with Amblyopia

Esotropia (one eye turns in relative to the other) commonly causes amblyopia.

 

exoStrabsimus without Amblyopia

Exotropia (one eye turns out) commonly does not cause amblyopia.

 

Man with Blue EyesAmblyopia without Strabismus

If there is a large difference in power between the two eyes, or a high refractive condition in both eyes, the amblyopia is not obvious to others.

What is Strabismus?

Strabismus means that the two eyes are not pointing to the same spot or position.

  • This may occur all of the time (constant) or some of the time (intermittent).
  • It can be the same eye that is mis-pointing (unilateral) or it can alternate, meaning that at times one eye points straight and at other times the other eye points straight. This is called alternating strabismus.

What is Amblyopia?

Amblyopia, also known as “lazy eye,” is the lack of normal visual development in the brain. The eye, as a structure, is healthy, but the wiring between the eye and the brain is underdeveloped for one of three main resaons (see below). Amblyopia means that the information from one, or both eyes have not had the opportunity to develop the wiring from the eye to the brain. If untreated, it can cause legal blindness in the affected eye. About 2% to 3% of the population is amblyopic.

Refractive Amblyopia:

  • Bilateral (both eyes) Amblyopia can occur if there is a high refractive condition that is about the same in both eyes.
  • Unilateral (one eye) Amblyopia occurs if there is a large difference between the two eyes. Usually, the eye with the higher refractive condition is the amblyopic eye, meaning the one that did not develop.

Strabismic Amblyopia:

  • When the two eyes do not point at the same position, then the Strabismus can bring on Amblyopia.
  • People are often told that nothing can be done past a certain age. This is simply NOT TRUE. It is certainly easier to address at a younger age, but both children and adults can be helped, even when they have had surgery to “correct” the lazy eye.
  • Click here to learn about children, adults and parents who tell their stories about Success with Lazy Eye, Crossed Eyes, etc..

Amblyopia signs and symptoms

Amblyopia develops because of lack of a clear signal from the eye to the brain. Amblyopia is in the brain rather than in the eye. Most often it begins at birth or during early childhood. It is often not obvious and therefore not noticed by parents, caregivers or pediatricians. Parents often feel guilty for not having realized that there is a problem.

What causes amblyopia?

Amblyopia may be caused by a number of conditions that affect typical eye and vision development. The two most common types are strabismic amblyopia and refractive amblyopia.

Strabismus is the condition where the eyes are not aligned, either all of the time (constant) or some of the time (intermittent). Esotropia is when one eye points (crosses) IN while the other eye points straight. Exotropia is when one eye points OUT while the other eye points straight. In either case, the two eyes aren’t able to work together, and the ability to use the two eyes together and then to see in 3D never develops.

Refractive amblyopia occurs when there is a large difference in power between the two eyes, or if someone is very farsighted or very nearsighted in both eyes. It’s important to correct amblyopia as early as possible, before the brain ignores vision in the affected eye.

On occasion, lazy eye is caused by other optical conditions such as cataracts or another structural impairment.

Treatment of amblyopia

Amblyopic adults and children can be treated with Vision Therapy. Vision Therapy enables the individual to develop vision and to learn how to use the two eyes together as a team.

Jillian’s Story is an account written by a mother about her frustration and disappointment and then ultimately her success. She was frustrated with her pediatirican and the lack of success and direction by her pediatrica optometrists. She ultimately found a Developmental Optometrist who enabled her daughter Jillian to gain vision in both her amblyopic eye and the ability to use her two eyes together as a team, through Vision Therapy.

Some doctors still prescribe placing a patch over the stronger eye to force the weaker eye to be used more. Patching alone typically does not work. Some doctors prescribe atropine eye drops to treat amblyopia rather than patching. The thinking is the same as the patch: blur the “good eye” to force the brain to use the amblyopic eye more.

Refractive Amblyopia occurs when there is a large difference in the power of the two eyes. Eyeglasses may be prescribed. At times, contact lenses are more effective in addressing and solving the amblyopia.

Strabismic Amblyopia occurs when amblyopia is caused by a large eye turn. Surgery does not solve the problem, but it makes the two eyes appear to look in the same direction, but it does not solve the underlying problem of the brain not using the information from one eye. The eye often goes back to its original position and then a second surgery is suggested. Remember, surgery does not solve the problem, but it makes the eyes appear to be straight.

Amblyopia does not go away on its own, and untreated amblyopia can lead to permanent visual problems and poor depth perception. If your child has amblyopia and the stronger eye develops disease or is injured later in life, the result will be poor vision through the amblyopic eye. To prevent this and to give your child the best vision possible, amblyopia should be treated early on.

Some doctors still think that amblyopia can only be treated when found in children, before the age of 8 or 9. Although it is easier to treat earlier, even adults have benefited from vision therapy for amblyopia, and even after they had been damaged by strabismus surgery. Please consider reading Dr. Susan Barry’s book, Fixing My Gaze. Dr. Barry is a neurobiologist and had had 3 surgeries for strabismus when she was young. She describes her difficulty learning because of the strabismus, how her parents had been told that vision has nothing to do with learning, and that she should just learn to live with this. Even as an adult, and even in her studies, she was told to accept this. As a nearly 50 year old adult, she developed the visual skills through Vision Therapy, was able to develop vision in each eye and learned how to use her two eyes together as a team.