Science Forums 2

[CraigD]

Arkain, I think you should take or self-educate the equivalent of an introductory physiology of psychology course, focusing on visual perception. This is a very mature subject, yet full of surprising and counterintuitive findings and ideas, which I think you should thoroughly master before attempting speculation such as you’re making in this thread.

A couple of features of visual perception that I think bear on your ideas in this thread:

• The human eye – specifically the retina – does not sense light in the way that photographic film or electronic video sensors do, but rather sense changes in light. If you actually hold your eye perfectly still – something impossible without artificial techniques such as injecting the ocular muscles with a paralyzing drug – you’ll quickly seen nothing – that is, become blind. Because your brain’s sight centers compensate for them, you’re unaware of them, but your eye muscles involuntarily shift the direction of your eyes very slightly (about 0.3°) about 60 times a second, movements know as microsaccades.
• Afterimages, such as the one you describe from glancing at the rising sun, are not due to the absolute luminosity, but due to a difference in the activation of nearby retinal cells. Note that one can induce a strong, long-lasting afterimage by staring for about a minute at fairly dim, strong-contrast images, such as the ones in the linked wikipedia article, then closing your eyes.

Although various encyclopedic summaries such as the above linked wikipedia articles give decent overviews of the physiology of sight, it is, I think, a subject that should be studied in the structured, methodic way typical of a course or textbook.