kassover@jupiter.crd.ge.com (David Kassover) (04/09/90)
In article <6404@ur-cc.UUCP> orin@cvs.rochester.edu (Orin Packer) writes: > > Stereo blindness is very common even though the person affected may > have otherwise unremarkable vision. Approximately 5% of the > population is unable to make use of stereopsis at all and another 25% > or so has some difficulty, such as being insensitive to just divergent > or just convergent disparities. > I've become intrigued by this. I have made small inquiry to someone who works at the Lighthouse in NYC. My contacts had no access any such statistics. This is not to say they don't exist. Perhaps the sources of the statistics could be posted? Or E-mailed, if this thread has become too tiresome. > The visual system undergoes a long period of calibration during early > development that involves refinement of the connections between > neurons in the visual cortex. This process is easily disrupted by > any problem that gives one eye an advantage over the other eye, such > as a congental cataract or an imbalance in the eye muscles, or even a > difference in the optical focus of the two eyes. Once the > binocular inputs to the cortical neurons are disrupted, they > apparently never recover even though visual acuity can usually be at > least partially restored by removing the underlying problem. I understand that generalizing from one example or counter-example is dangerous when one is dealing with people. But I know of one person who had an "eye muscle imbalance" corrected when he was in his mid-to-late twenties. He still has more than adequate depth perception, the problem (at least for a while after the surgery) was that he had never had INVOLUNTARY depth perception. Just as a hint, he is an author of several of the papers that gets referenced here every so often. And just to be incredibly rude, I wouldn't mind in the slightest if he would join the discussion once in a while.