Childhood visual experience affects adult voluntary ocular motor control

Purpose. To quantify the effects of childhood visual experience/chronic vis ual deprivation upon adult voluntary ocular motor control. Methods, Eye mov ements of blind and sighted adults were elicited and videotaped in total da rkness. The videotaped responses were digitized using an eye tracker, yield ing data from 10 congenitally blind (infantile onset, blindness before age 1 year), 16 adventitiously blind, and 9 sighted persons, Results, Multivari ate analysis of variance, trend analyses and post hoc tests revealed that p rimary position fixational stability and consistency of return to primary p osition were lowest in the congenitally blind vs. the adventitiously blind group, and highest in the sighted, Duration of adventitious blindness reduc ed primary position stability but not consistency of return to primary posi tion. Secondary position maximum amplitudes: congenitally blind mean, 14 de grees; adventitiously blind mean, 40 degrees; sighted mean, 47 degrees. Ave rage velocity (a form of Main Sequence) increased significantly with amplit ude in all three groups. Conclusions. Visual deprivation can greatly attenu ate but does not abolish human voluntary eye movement, Adventitious blindne ss exerts minimal to profound effects, commensurate with age of vision loss .