Lazy Eye is a common term used to describe a condition where one eye sees poorly, even with eyeglasses or contact lenses. The proper medical term for this condition is Amblyopia. The term "lazy eye" is also mistakenly used to describe an eye turn or crossed eyes, which is known as Strabismus. This is inaccurate. A crossed eye can cause Amblyopia, but it is not necessarily a "Lazy Eye."
Lazy Eye can develop in childhood due to:
- An obstruction of vision within one eye due to injury or disease;
- Significant differences between the clearness of the images seen by each eye due to farsightedness, nearsightedness or astigmatism;
- Misaligned eyes or crossed eyes (Strabismus)
When the clarity or alignment of the images from the two eyes is very different, or if the child sees double, the brain may begin to ignore the vision in one eye. This can result in amblyopia. The favored eye compensates for the "lazy eye," so the child with amblyopia may not be aware of the problem until the better eye is covered.
It is important to note that amblyopia can be present when there is no physical problem with the eye itself. Disease or injury are just a few of the possible causes of amblyopia. There are many reasons why a person may develop amblyopia. It is important that a doctor determine the cause and provide the appropriate treatment.
Amblyopia is generally treatable even after age eight, although the earlier the problem is found and treated, the more successful the outcome.
Treatment may include:
- Eyeglasses or contact lenses (proper lenses can help reduce stress so that the under-used eye can start to work more efficiently);
- Forcing the weaker eye to work by blocking or fogging the favored eye with special lenses, an eye patch or eye drops;
- A program of Vision Therapy to help equalize vision in both eyes, improve eye coordination, and restore clear single vision.
Dr. Sue Barry, perhaps the most famous amblyopia patient, was featured in an article in The New Yorker in June, 2006. As a result of a lazy eye, also known as Amblyopia, Dr. Barry lost stereo vision when her brain "turned off" the image it received from the lazy eye. Stereo Sue, a title she gained from The New Yorker article, was a patient of Dr. Theresa Ruggiero. Sue was able to gain stereo vision after a year of vision therapy. Dr. Barry said that gaining stereo vision made her feel more a part of the world, "an incredible sense of being immersed in the space around you, as opposed to looking in on it from a slight distance away." Sue's story was featured in the COVD journal, Optometry & Vision Development (OVD), in which she wrote an editorial about her experience.
Read Sue's articles in OVD 37-2
Read The New Yorker article on Stereo Sue
NPR's Joe Palca was born with a crossed eye. So as not to be confused by two different images, his young brain learned to suppress the input from his right eye, leaving Joe with no stereo vision. Joe met with optometrists at the University of California, Berkeley, where he was diagnosed by Dr. Dennis Levi as stereo blind. Joe contacted Dr. Sue Barry, who also had amblyopis as a child which caused her stereo blindness. Now Joe is working to gain stereo vision, and teach his old brain new tricks.
Read and listen to the NPR story on Joe Palca