One fixates accurately in order to see clearly not because one sees clearly.
Binocular gaze was measured accurately under natural conditions with the Maryland Revolving Field Monitor to determine how visual-clarity affects gaze-accuracy. The gaze of 3 unrestrained, seated subjects (2 presbyopes and 1 myope) was recorded as they tapped 4 LEDs with a long, narrow rod cemented to a thimble worn on their index fingers. They wore positive contact lenses, permitting very clear vision only nearby, within 35 cm. This task was hard. It took more than 7 seconds to complete. Gaze-accuracy varied inversely with target-distance. Gaze was less accurate when targets were nearby, and seen clearly, than when targets were farther away and harder to see. This result was not anticipated. It implies that gaze is accurate in order to see clearly and not because targets can be seen clearly.
Steinman
Robert M
RM
Department of Psychology, University of Maryland, College Park, MD 20742-4411, USA. steinman@brissio.umd.edu
Pizlo
Zygmunt
Z
Forofonova
Tatiana I
TI
Epelboim
Julie
J
D000328:Adult; D000368:Aged; D003261:Contact Lenses; D005385:Fingers / Q000503:physiopathology; D005403:Fixation, Ocular; D006801:Humans; D007858:Learning; D009043:Motor Activity; D009216:Myopia / Q000503:physiopathology* / Q000523:psychology; D011305:Presbyopia / Q000503:physiopathology* / Q000523:psychology; D012438:Saccades; D014792:Visual Acuity