Performance evaluation of visual fixation

Fixation has been considered to be the smooth pursuit with stationary target and a type of eye movement when saccades are repressed. The evidence can be manifested in the slow control model consisted of a position channel and a velocity channel in precisely delineating the characteristics of visual fixation. Bivariate ellipse contour area and root mean square (RMS) of the velocity profile are used as the evaluating parameters in the study of visual fixation performance. The results show that the bivariate area is significantly reduced as the age increased. The RMS of the velocity profile is, however, not affected. For patients with vertigo, both bivariate area and velocity RMS increase significantly. It has been found the bivariate contour area is sensitive and efficient in differentiating the old from the young and the patient from the normal age-matched subjects and might be proposed as a parameter for clinical application in diagnosing abnormal syndromes for the patients.