[FoRK] self-eye-poking

[Zee Roe]

http://web.mit.edu/newsoffice/1993/eye-0127.html

Close your eyes and gently rub the outside corner of one eye. Press a
little harder. What do you see?

If you're like many of the approximately 50 participants at a talk last
week by Jeremy Wolfe, visiting associate professor in brain and cognitive
sciences, you saw a small white spot, or a black spot with a white rim.
But where does the spot come from? What causes it?

[...]