Magic Eye, convergence, eye spacing

[P3D Dr. George A. Themelis <fj834@xxxxxxxxxxxxxxxxxxxxx>]

Wolfie writes:

>"Just like those Magic Eye books"
>however, not many of my friends can see those either.

I have made a few nice copies of those for demonstration.  I show them to
people with my red button viewer.  Most people can see them and are
impressed.  I ask them to close one eye and the stereo image disappears. 
It is a very good demonstration.

However, some people still cannot see them.  I discovered that those who
cannot see them (they see a flat image) do so because they converge their
eyes while looking through the viewer.  The trick is to relax the eyes as
you do when looking at regular stereo pictures.  Some people can jump
between the flat and stereo image by changing their eye convergence.

I have told people that those who can see them have a healthy stereo
vision, while no conclusion can be drawn for those who cannot see them.

>Interestingly enough a vietnamese friend couldn't see the slides in my
>little viewer....  I wondered if his eyes were so different that the
>viewer was no good to him.
 
Quite possibly his eye spacing is considerably smaller than the spacing
of the lenses in this viewer.  People with small eye spacing might have
trouble using any slide viewer.  Try to measure his eye spacing with a
ruler while he is gazing at infinity.

-- George Themelis


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