The medical term for a “lazy eye” is amblyopia. Amblyopia usually causes one eye to have reduced vision due to abnormal visual development early in life, though in some cases both eyes can be affected. The abnormal visual development causes the information pathway between the eye and the brain to become altered, and the weaker eye then receives reduced visual input. The brain then tends to ignore the weaker eye, which in turn affects the eyes’ ability to work together properly.
People often think of a lazy eye as an eye that turns in/out (strabismic amblyopia) but that’s only one of the three types of amblyopia. The second type is called deprivation amblyopia, which means that there is a problem with the eye that is prohibiting clear vision – for example a cataract that is blocking light from getting into the eye. The third type is called refractive amblyopia which means the weaker eye has a significantly higher prescription than the other. This is often due to the weaker eye being much more farsighted but can also be from the weaker eye having more astigmatism or nearsightedness. The second and third types of amblyopia are not immediately evident when looking at the appearance of an individual, which is why regular eye exams are so important. If amblyopia is untreated it will lead to permanent reduced vision in the weaker eye. Thankfully, if caught early we can reverse the amblyopia, meaning amblyopia is preventable! Amblyopia has the best chance of being fully corrected if the patient is diagnosed and properly treated by approximately age seven.
Symptoms to look for:
- squinting/shutting one eye,
- head tilting,
- trouble with depth perception.
Risk factors of developing amblyopia: premature children, family history of amblyopia, developmental disabilities.
Amblyopia is often treated based on the type that is present. This can range from full time glasses wear to surgery. It is common to see a child with amblyopia wearing an eye patch. The purpose of the eye patch is to strengthen the weaker eye by patching the good eye to force the brain to use the weaker one.
We recommended children having their first eye exam at six months old, again at two years old and then every year after to ensure that the eyes are developing as they should.
Written by Dr. Samantha Laudinsky