ИСТИНА

The variability of smooth pursuit (SP) eye movements was studied in a group of healthy elderly subjects (n=34, the mean age being 61 years) for horizontal apparent motion with a method that does not require direct measurements of eye movements. It was found that the mean smooth pursuit gain in this group as well as in the group of young adults was distinctly differentiated with respect to the individual smooth pursuit efficiency. Both groups were represented by three different types of subjects, the ratio of which was identical for elderly and young ones. This fact demonstrates that the human oculomotor system is relatively resistant to the effects of aging. At the same time, an appreciable increase of percentage of persons with directional asymmetry of smooth pursuit has been found among elderly adults. A higher smooth pursuit efficiency was noticed reliably more often in the direction from left to right rather than in the opposite direction. Subject eye movements were recorded with an i-View XTM Hi-Speed 1250 eye tracking system (SMI Inc., USA). These records confirmed that the SP accuracy of older adults is less than that of young persons, at least in some directions of tracking.