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Topics > Healthy Outlook > Early Treatment is Key to Preventing Lazy Eye

Early Treatment is Key to Preventing Lazy Eye

Published by Contra Costa Times

Posted on Wed., April 21, 2010
By Melody Haworth, COA

IMAGINE YOU HAVE a child who dreams of becoming a surgeon, a pilot, or a structural engineer. An eye condition undetected in infancy or in early childhood could prevent your child from fulfilling his or her dreams.

Amblyopia (am blee OP ee uh) or "lazy eye," refers to a disorder in which the brain does not develop clear vision equally in both eyes. Amblyopia is fairly common, affecting one or both eyes in 2-3 out of every 100 people. It is often not known that a child has it because children do not know what to expect from their vision. And parents are unaware their children are not able to see the same in both eyes.

To understand amblyopia, it is important to know a little bit about how vision works.

Both eyes see the world separately, so the brain receives slightly different pictures from each eye. Then the brain combines the two into one picture with three dimensions.

If each eye sends a very different picture from the other, the brain is unable to combine them, and is forced to choose only one eye to represent the original picture. This results in amblyopia. The ignored eye no longer receives enough valuable brain energy to develop its own maximum potential for vision.

There are three major reasons eyes do not create equal images, all of which can be addressed if caught early in life.

Refractive Error

A refractive error refers to the picture quality that is created by the eye based on its size and shape. Amblyopia may result if both eyes are not of equal size and shape. When one eye is longer (myopia or nearsighted), shorter (hyperopia/farsighted) or oddly shaped (astigmatism) in comparison to the other eye, glasses are prescribed to prevent amblyopia.

Patching of the "good" eye may also be required to help the "bad" eye develop equal vision. If patching is not tolerated, atropine eye drops may be prescribed as therapy.


The alignment of the eyes is very important for the brain to create one image.

If the images received by each eye are displaced so much that they cannot be overlapped, amblyopia results. To correct this, alignment needs to be maintained in both eyes with prescription glasses, or surgery may be required.

Clarity of Image

To see an image correctly, the retina (at the back of the eye) must receive an unobstructed light signal sent through the eye. If any of the eye structures are opaque or damaged, the light signal is interrupted and amblyopia can occur. Surgery, patching of the "good" eye, and/or prescription glasses may prevent amblyopia.

Children should have their vision checked when their doctor does a "physical", and at the beginning of each school year.

Even if a child seems to see normally, (amblyopia may not bother a child), s/he should be seen by an ophthalmologist (a doctor of eye disease) if she or he:

  • Prefers one eye to the other
  • Bumps into objects repeatedly on one side
  • Has "red eye" only on one side in photos
  • Has a cloudy, whitish pupil
  • Has eyes that appear to be looking in different directions
  • Has a family history of amblyopia, retinoblastoma, strabismus, and/or congenital cataracts.

Ms. Haworth is a certified ophthalmic assistant with Contra Costa Health Services, the county health department.

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