The effect of defocusing the image on the perception of the temporal order of flashing lights.

The temporal interval between flashing lights that is required to perceive nonsimultaneity decreases as the refractive error increases from 0 to +2 diopters. The interval then remains constant with further increases to 3 and 4 diopters. The results are discussed in terms of the relative increase of transient to sustained visual channels and of the increase in apparent movement.