Checkerboards and Honeycombs in the Sun
In 1819, the eminent physiologist Johann Purkinje drew the following picture of what he saw when he closed his eyes and faced toward the sun:
Purkinje said that most individuals with whom he tried this experiment report seeing such figures, especially the little squares. (For a fuller translation of this and surrounding passages, see here.)
When I face the sun with eyes closed it doesn't seem to me that I see checkerboard or honeycomb shapes. Rather, I'd say, my visual field is broadly and diffusedly orange or light gray (slowing shifting between these two colors) -- and brighter, generally, in the direction of the sun. Sometimes it briefly becomes a vivid scarlet. Others I've asked to close their eyes and look at the sun also generally don't report Purkinje-like experiences (although one person on one occasion -- out of several occasions -- reported something like a honeycomb latticework).
So I'm curious: Was Purkinje simply mistaken? Did he have unusual experiences, accurately reported for his own part, and then subtly pressured his subjects into erroneously reporting similar things? Could this be the kind of experience that varies culturally? I'd be interested to hear if any of you experience checkerboards or latticworks.