The flickers are called saccades. [1] It's not clear to me how, in the absence of head movement, eye movement alone would account for perceiving shading differ

The flickers are called saccades. [1] It's not clear to me how, in the absence of head movement, eye movement alone would account for perceiving shading differences. http://en.wikipedia.org/wiki/Saccade http://en.wikipedia.org/wiki/Saccade