How the Brain Sees
Normally, the brain receives 2 images at slightly different angles, and it combines them to produce a 3-dimensional (3D) image. This is not the case with amblyopia.
With amblyopia, the brain suppresses the information that comes from the affected eye, which turns off binocular vision.
Common signs and symptoms include:
An eye that wanders
inward or outward
Eyes that appear to
not work together
shutting an eye
If left untreated, amblyopia can lead to permanent visual impairment
Nearly 3% of adults experience permanent vision loss because of amblyopia
- Affects between 3% to 5% of children under the age of 6
- Can result in permanent vision problems in children as early as age 10 without treatment
- Affects more than 6 million adults in the US, who are untreated for the condition
- Affects all races and genders
- Affects more than 9 million people in the US and more than 210 million people worldwide
- Is responsible for more vision loss in people 45 years and younger than all other eye diseases and trauma combined
- Is significantly more difficult to correct as an adult if not corrected during childhood
3 possible causes that can lead to visual confusion
Amblyopia occurs when the affected eye sends blurry or distorted images to the brain. Because the brain doesn’t know how to interpret these visuals, it may learn to suppress visual inputs from the affected eye.
There are 3 common types of amblyopia:
- Refractive amblyopia causes light to bend on the retina, leading to blurry vision in that eye.
- Strabismic amblyopia causes the familiar crossed-eyed appearance, which leads the brain to suppress visual input from the eye that is not straight.
- Deprivation amblyopia occurs when light is partially or completely blocked from entering into the affected eye. This type of amblyopia may affect both eyes. Common causes include cataracts (a clouding of the lens) and ptosis (a droopy eyelid that sits low enough to block the light from entering into the eye).
*National Eye Institute. Facts about amblyopia. nei.nih.gov/health/amblyopia/amblyopia_guide. Accessed June 29, 2017.
Amblyopia affects more than just the eyes
Amblyopia can have a significant impact on children and adults, beyond their vision. The condition may cause some to struggle with a negative self-image, making it difficult to keep up in school or to participate in sports and other activities. Poor eyesight may also make it difficult to drive, find work, and maintain a sense of autonomy.