Abstract
Abstract: :
Purpose: The purpose of this study was to examine monocular optokinetic symmetry in younger and older adults. Methods: Twenty–four older (62+ years) and eighteen younger (19–28 years) adults were asked to monocularly view stripes that were moving in either the nasalward or temporalward direction. Optokinetic eye movement were videotaped and scored for the number of beats per second of looking time. Results: Overall, both younger and older subjects showed small but significant asymmetries of OKN. However, two–thirds of older subjects had asymmetries that were larger than/fell outside the 95% confidence interval of younger subjects. While these asymmetries were small, older subjects showed significantly larger asymmetries than did younger subjects. No significant differences were found between older and younger subjects in the number of beats for nasalward motion. However, fewer beats were found in older subjects for temporalward motion relative to younger subjects. Older subjects also showed more within subject variability for OKN to temporalward motion than did younger subjects. Conclusions: We conclude that asymmetries found in older adults might represent changes that are occurring within the binocular visual pathway that mediates OKN.
Keywords: aging: visual performance • motion–2D • eye movements