Picturing peripheral acuity.
The grain of the retina becomes progressively coarser from the fovea to the periphery. This is caused by the decreasing number of retinal receptive fields and decreasing amount of cortex devoted to each degree of visual field (= cortical magnification factor) as one goes into the periphery. We simulate this with a picture that is progressively blurred towards its edges; when strictly fixated at its centre looks equally sharp all over.
Anstis
S
S
Department of Psychology, University of California at San Diego, La Jolla 92093-0109, USA. sanstis@ucsd.edu
D006801:Humans; D009903:Optical Illusions; D014792:Visual Acuity; D058609:Visual Field Tests / Q000295:instrumentation / Q000379:methods; D014794:Visual Fields