The Mudcat Café TM
Thread #138956   Message #3193091
Posted By: JohnInKansas
22-Jul-11 - 06:41 PM
Thread Name: BS: Left-Handism
Subject: RE: BS: Left-Handism
Leenia -

There is a vision defect called "lazy eye syndrome" in which one eye doesn't focus with a view consistent with the other, and the "better" eye becomes so dominant that the other one just sort of "gives up."

A treatment a century ago, and at least until perhaps the 50s in some parts of the US was to put a patch over the good eye to force the weaker one to work, on the theory that it might "catch up." Although that treatment apparently had some success, it apparently worked best for the very young and I don't believe it's used much any more.

One "explanation" I've heard of claims that "lazy eye" is usually associated with a "convergence error." The eye must adjust the lens to focus at a certain distance, and both eyes must, ideally, focus at the same distance in order to both see the same object. In addition, for a near object each eyeball must "rotate inward" to "point at" the object.

If the two eyes are focused to the same distance but are "pointing in different directions," the view is obviously going to be messed up. If both eyeballs point at the same object, but focus at different distances, the result is pretty much the same. The "convergence angle" between the directions the two eyes point must match the focus distance in order for the two views to be consistent.

A consistent "convergence error" might sometimes be corrected with a "wedge lens" that bends the direction for one eye to bring the two views together, and claims have been seen that this can help recover a weakened "lazy eye." It's been far too long since I've looked at this subject though to be able to guess whether that's still considered a viable approach to the problem, and I certainly have no way to guess whether your "eyeball discrepancies" are in any way related.

Nearly everyone has some difference in focal range of their two eyes, but an extreme difference suggests a need to look at whether there's some subtle cause for which some corrective action is available.

I would presume that you do get regular examinations and consultations from a qualified vision professional, of course.(?)

John