My left eye is rather nearsighted (myopic); my right eye is slightly farsighted. This means that I have almost no depth perception --- a significant handicap in playing some sports, in trying to squeeze into tight parking spaces, or in viewing 3-D random-dot stereograms.

But on the happy side, in spite of the usual middle-age presbyopia that set in several years ago I find that I don't need reading glasses or bifocals. I read comfortably with one eye, and see distant objects sharply with the other. The brain has adapted over the years so that (except sometimes when I'm tired or ill) there's no double vision. (But maybe I should get a monocle, so that I can look like a Prussian officer, or a scruffy version of the New Yorker's annual "Eustace B. Tilley" cover twit?)

In the next generation, there's a fascinating phenomenon to report: all three of PD's and my children are, like their father, nearsighted in one eye and normal-to-farsighted in the other. But strangely enough, they're mirror images of me --- for every one of them the right eye is myopic, and the left is built with a nearly normal focal length. What genetic or evolutionary reason could there be for such a flip-flop? I'm mystified....

TopicPersonalHistory - 2001-11-23

Mmm... identical twins are actually mirror images of each other, so the likely explanation is in how the initially unbiased cells develop L-R characteristics to begin with. Intriguing thought that our genes would flip-flop through the generations... -- Bo Leuf

(correlates: HerodotusOnWarAndPeace, UpsideDownShadows, SkyLights, ...)

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