The fusion illusion.
D004192:Discrimination, Psychological; D004292:Dominance, Cerebral; D005403:Fixation, Ocular; D006801:Humans; D007088:Illusions; D008297:Male; D009903:Optical Illusions; D009949:Orientation; D014785:Vision, Ocular; D014792:Visual Acuity; D014794:Visual Fields