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Eye and Vision Care

Eye exam

07/15/2009

Question:

i took an eye exam to renew my liscense. there was three columns and I could only see the left and right column I could not see the middle until I closed one eye. I was wondering why?

Answer:

The vision screenings typically done when applying for or renewing a driver's license are performed in what we call a stereoscope. This apparatus is able to show charts that are seen by the right eye, the left eye, and by both eyes. Sounds like you did not see a chart that was only shown to one eye (let's say the left eye) until you closed your right eye. Here is probably the reason:

In normal binocular vision, our brain fuses the images seen by both eyes into one image. This requires very good eye alignment and eye coordination. If the eyes are not perfectly aligned, double vision can result. As double vision can be very bothersome, our brains will often suppress or turn off the image coming from one eye. This allows us to see single again. The suppressed eye is still functional, the brain just ignores the information coming from it. If the other eye is covered, the brain will again "pay attention" to the information coming from the previously suppressed eye.

Your eye doctor will be able to determine if you have a binocular vision disorder that would have led to this suppression and if any treatment is recommended for it.

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Response by:

Andrew J Toole, OD, PhD, FAAO
Clinical Assistant Professor of Optometry
College of Optometry
The Ohio State University