SMALL EYE MOVEMENTS AND VISUAL EFFICIENCY

PREVIOUS WORK BY FOLEY-FISHER SHOWED THAT A CLOSE RELATIONSHIP EXISTED BETWEEN THE FREQUENCY OF SMALL INVOLUNTARY EYE-MOVEMENTS (SACCADES) AND VERNIER ACUITY. THE PRESENT RESEARCH IS AN EXTENSION OF THIS WORK, USING RANDOMLY SELECTED UNTRAINED SUBJECTS RATHER THAN EXPERIENCED OBSERVERS. IT WAS HOPED THAT RESEARCH WOULD SHOW THE SACCADE FREQUENCY/ACUITY RELATIONSHIP TO BE GOOD ENOUGH FOR PREDICTION OF ACUITY ONCE THE EYE- MOVEMENT PARAMETERS WERE ESTABLISHED BY OBJECTIVE MEASUREMENT. THE RELATIONSHIPS FOUND WERE SO POOR THAT THIS WAS NOT POSSIBLE. HOWEVER, THE GENERAL TREND OF THE RESULTS WAS IN AGREEMENT WITH PREVIOUS WORK, THE BEST INDICATOR OF GOOD VERNIER ACUITY BEING THE FREQUENCY OF INTER-SACCADIC INTERVALS LONGER THAN ABOUT 1 SEC. THIS AND OTHER RESULTS SUPPORT A HYPOTHESIS THAT VERNIER ACUITY IS LIMITED BY AN INTEGRATION PERIOD DEFINED IN DURATION BY THE INTERVAL BETWEEN SACCADES. A LARGE BODY OF EYE-MOVEMENT DATA IS PRESENTED FOR USE BY OTHER WORKERS ENGAGED IN RESEARCH ON EYE- MOVEMENTS. /AUTHOR/