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.