Amblyopia (Lazy Eye)

It is not easy to recognize amblyopia. A child may not be aware of having one strong eye and one weak eye. Unless the child has a misaligned eye or other obvious abnormality, there is often no way for parents to tell that something is wrong. Amblyopia is common, affecting approximately two or three out of every 100 people.


Some people will experience the following symptoms:

  • bad or blurry vision

  • poor depth perception

  • poor spatial acuity

  • reduced sensitivity to contrast or motion

The different types of amblyopia include:

Form-deprivation and occlusion amblyopia: This type can occur if there is any corneal scarring (such as with forceps injuries during birth) that prevents proper development.

Refractive or anisometropic amblyopia: This is the type that occurs when there's a strong difference in the vision quality between the two eyes, but it doesn't have the same physical manifestation (the "lazy eye") as strabismic amblyopia. Unfortunately, this means it can go undiscovered by pediatricians during regular childhood check-ups.

Strabismic amblyopia: This type is most commonly called "lazy eye." If it forms during the adult years, it commonly causes double vision. However, in children, the stronger eye suppresses the weaker one. Strabismic amblyopia is the easiest type to recognize since the weaker eye often looks and behaves differently.


To correct amblyopia, a child must be made to use the weak eye. This can be done in several ways. Most often amblyopia is treated by patching or covering the child's strong eye for weeks or months.

Another method is prescribing glasses to correct errors in focusing. If glasses alone do not improve vision, then patching is necessary. Amblyopia may also be treated by blurring the vision in the good eye with special eye drops or lenses. This forces the child to use the "lazy" eye.

Even after vision has been restored in a weak eye, part-time patching of the strong eye may be required to maintain the improvement. If we find a cataract or other eye problem, surgery may be required to correct that problem. Patching may still be necessary even after surgery. Amblyopia cannot usually be cured by treating the cause alone. The weaker eye must be strengthened in order to see normally.

Without treatment, several problems may occur: the amblyopic eye may develop a serious and permanent visual defect; depth perception (seeing in three dimensions) may be lost; if the good eye becomes diseased or injured, a lifetime of poor vision may be the result.

Success in the treatment depends upon how severe the amblyopia is and how old the child is when treatment is begun. Children do not like to have their eyes patched, so parental care and involvement is essential.


Amblyopia is detected by testing the vision in each eye. Since it is difficult to measure vision in young children, we often test how well a baby follows objects with one eye when the other eye is covered. Using a variety of tests, we observe the reactions of the baby when one eye is covered. If there is a weakness in the uncovered eye, the baby may try to look around the patch, try to pull it off, or cry.

We will also carefully examine the eye to see if other eye diseases may be causing decreased vision. These diseases include cataracts, inflammations, tumors, and other disorders of the inner eye.

Causes/Risk Factors

Any condition that affects normal use of the eyes and visual development can cause amblyopia. In many cases, the conditions associated with amblyopia may be inherited. Amblyopia has three major causes. It occurs most commonly because of strabismus, or misaligned eyes.

Another cause is refractive error, which means one eye is out of focus because it is more nearsighted, farsighted, or astigmatic than the other.

The other main cause of amblyopia is cataract or other disease that causes clouding of the eye's naturally clear lens. Any factor that prevents a clear image from being focused inside the eye can lead to the development of amblyopia in a child. This is often the most severe form of the condition.

If you have been diagnosised with or suspect you have Amblyopia please call our office at (518) 220-1400 to set up a consult