A.A.Spilman

What do we see?

When we look at a bright sky, at white snow or an electric bulb, it is possible to see undistinguished whitish "dots" moving chaotically.

What's that? Dust? If so, why their movement does not depend directly upon the motion of the air (upon the wind)?

And why do we see these "dots" only in the case of special focusing of the eyes?