The Effects of Age and Visual Capability on Performance with Plane and Convex Mirrors

Reaction times were measured for a detection task and a recognition task when using plane mirrors and when using convex mirrors. Three groups of nine drivers each (Young, Mature-with Bifocals, and Mature-No Glasses) were studied. The detection task consisted of reporting the number of Landolt Rings (0,1,2,3, or 4) that were made to appear in a mirror. The recognition task consisted of reporting the orientation (left, right, up, or down) of the Landolt Ring gaps. On both the detection and recognition tasks differences between types of subjects increased as the convexity of the mirror increased. The largest differences occured when the images were displayed in a 40 inch convex mirror. Here, Mature-No Glasses subjects took .77 seconds longer to report target orientation than Young subjects. On the same task Mature-Bifocaled subjects took only .18 seconds longer than the Young subjects. Since the longer reaction times of Mature-No Glasses subjects appears to be due to their poorer visual acuity it is recommended that states require higher visual standards with respect to far visual acuity.