Amblyopia (Lazy Eye)
Sometimes called lazy eye, amblyopia occurs when vision is blurry even when wearing glasses. This occurs because the brain hasn’t learned how to interpret what a “clear” image should look like. If a child doesn’t use an eye because it is turned, we call this Strabismic Amblyopia. If a child doesn’t use an eye because of a high uncorrected glasses prescription, we call it Refractive Amblyopia. Neuroscientists once believed that this issue was not treatable after the “critical period”, which ended at age 6. However, we now know that amblyopia can be corrected years after the critical period, including into adulthood!
- Poor depth perception
- Poor hand-eye coordination
- Favors one eye more than the other
- Clumsy, bumps into things
- Poor overall school performance
Strabismus (Exotropia or Esotropia) from an early age can cause ambylopia if left uncorrected. The reason for this is that when an eye is turned, the brain suppresses (ignores) the vision from the turned eye to prevent double vision. Ambylopia is more likely to occur over time if the eye turn is constant or frequent, versus those with intermittent eye turns.
Refractive ambylopia occurs when a refractive error (glasses prescription) is left uncorrected during the first few years of life. Often, refractive amblyopia is significant worse in one eye while mild or absent in the other. Usually the eye with the stronger prescription has amblyopia. Meridional Amblyopia is a type of Refractive Amblyopia that occurs with high amounts of astigmatism.
Treatment of Strabismic Amblyopia
Treatment of amblyopia as a result of Strabismus is similar to treatment of Strabismus (read more HERE). In addition to treating the eye turn with Vision Therapy, we also work on improving the clarity, visual skills, and awareness of the amblyopic eye during therapy. We quickly teach patients to integrate and use both eyes simulataneously by using time-tested techniques as well as new technology. While the amblyopic eye doesn’t always return to a level of clarity as the non-amblyopic eye, they typically learn to use both eyes together to see depth and improve visual skills needed for reading, playing sports, and many other activities.
Treatment of Refractive Amblyopia
Our first goal in Refractive Amblyopia is to properly correct the uncorrected prescription. This may involve glasses, bifocals, and often times, contact lenses. Once the patient is adapted to wearing the correct prescription, we focus our efforts in Vision Therapy on improving clarity, comfort, and visual skills in the amblyopic eye. These visual skills include eye tracking, focusing from near to far, fixation, and much more. We work to quickly integrate both eyes and improve binocular vision at a rapid rate by using activities that give 3-D feedback to the patient. This feedback helps to reinforce to the patient that both eyes are working together again.
Patching and Eye Drops
Some doctors prescribe patching or eye drops to help penalize the good eye and force the amblyopic eye to work on its own. While we do use patching to some extent in Vision Therapy, it should not be used as the sole treatment for amblyopia. Research shows that ambylopia is not just a “good eye” and a “bad eye” but rather two eyes that don’t work well together. The brain has certain areas of the primary visual cortex that are only used when both eyes are working together. So even though the “good eye” is clearer, it still isn’t living up to its potential when it doesn’t have a partner! Binocular Vision Therapy addresses this by training both eyes together, something that patching and eye drops can’t do.
Clinical Research in Amblyopia
Amblyopia Treatment – Eye Patching Alone is no Longer the Standard of Care – Dr. Dan Fortenbacher, FCOVD
Amblyopia Research Compilation – Vision Help Blog, Dr. Len Press, FCOVD
Amblyopia Research Supports Treatment Without Patching – Dr. Nate Bonilla-Warford
Developments in Amblyopia Treatment – Dr. Coralee Mueller