For those members of the general public who derive some strange sense of pleasure out
of viewing the meaningless patterns in Magic Eye
books, it must be hard to understand there are people who cannot, never, no way,
experience the illusion of depth from these Magic Pictures. Now be a sport and don't
harass your cross-eyed nice, neighbour or colleague with "You just need more
practice, and by the way, I don't understand you don't see anything in them - I need to
cross my eyes to see it, and yours are already crossed!" There are lots of random dot
stereograms and other Magic Pictures on the Web already, so it's high time somebody sets
the record straight with a at least one example of how the world looks like according to
somebody with a somewhat screwed up binocular system.
Search the differences! There aren't all that many. Some objects or pieces of objects that contrast highly to their surroundings are duplicated, sometimes things appear slighlty undefinable. These things are easily ignored. If there is a problem at all with perceiving things like this, it arises from ignoring too much of the visual input, like glass doors, bikes parked on the sidewalk, and not noticing a friend (or worse, your boss) waving to you from across the street.
It gets even more interesting (when your browser supports displaying "animated .GIF's") and when suppression fails to do a nice full-time job of avoiding diplopia (see the page about amblyopia, diplopia and confusion):
Note: This image does not display well in some versions of Netscape.
There is almost nothing written about the differences in perception between
"normal" people and those with (congenital) strabismus. (If you know of any
literature references about this, please e-mail
me now!) So.. Are there any differences at all? It has been established strabismus induces
a different development of Visual Area 1 (a drastically reduced number of binocularly
driven cells), and as V1 provides input for all other visual areas, it makes me wonder
what the neurological differences are further along the path, and what the impact of these
changes would be.