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What is lazy eye anyway? Some definitions.

One of the most persistent misconceptions I encounter is the idea that everyone who has an eye turn is termed to have a “lazy eye.” The easiest way to explain is to first define a few terms. “Lazy eye” is the lay term for amblyopia which the dictionary defines as “impaired vision with no discernible damage to the eye or optic nerve.” The result of that impaired vision is that the eye is not able to be corrected to 20/20 and the person compensates by using only the other eye. Eye teaming with an impaired eye is usually not worth the trouble and often the person doesn’t know how to use both eyes together anyway. The eye which is not being used turns in and is then considered a “lazy eye.” Opthalmologists treat the condition by patching the weaker eye, which sometimes improves the vision in that eye, but does nothing to help the eyes work together.

My diagnosis is strabismus, which the medical dictionary defines as “a visual defect in which one eye cannot focus with the other on an objective because of imbalance of the eye muscles. Also called heterotropia squinttropia.”  Choosing this definition allows the medical community to focus on correcting the defect with surgery. Successful surgery is defined as a cosmetic fix (no visible turn) but the eyes are still not focusing together, so the strabismus remains. If the patient is lucky enough to have vision therapy in connection with surgery, a cure becomes much more likely. An example of this would be my brother, who had three eye surgeries as a child and now has no eye turn, yet people ask him if he is looking at them. Strabismus can lead to amblyopia if the person uses just the dominant eye.

Nowhere in the standard dictionary definitions is there a real description of the WHY of strabismus. My understanding of why my eyes take turns instead of working together is that it is a compensating mechanism. If I choose to look out of both of my eyes at the same time, I actually experience diplopia, “a visual defect in which a single object is seen in duplicate; double vision. It can be caused by incorrect fixation or by an abnormality in the visual system.”  I mentioned in a previous post that I was creating diplopia, or double vision, by working on my own with the Brock string. Since I don’t want permanent double vision, we are concentrating on peripheral vision and strengthening other visual skills in vision therapy. Suppressing the sight in one eye (often by turning the eye) avoids double vision.

When I look out of my dominant right eye, my left eye now avoids double vision by turning in. If I switch to the left eye, the right turns in (and it’s a larger turn). No, my eyes are not lazy, they just don’t know how to work together yet more than 12 inches from my face. (And the deviation was not always as noticeable as it is now.) I actually can see the 3D effect in the Magic Eye books if I hold them really close to my face, but my doctor discourages that because we are working to extend my range of fusion. The inward turning of the eye is called esoptropia (es-uh-troh-pee-uh) or “strabismus in which one eye deviates inward.” Barbra Streisand is famous example of someone with esotropia. The opposite of this is exotropia or when one eye deviates outward (also called “wall-eye”). A well known person with exotropia is Martha Stewart.

martha-stewart      Barbra Streisand

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