A novel approach to the assessment of afferent pupillary defects.

The pupil response to a flashing light stimulus was observed for a group of 26 healthy volunteer controls, and 15 patients with relative afferent pupillary defects (RAPDs). For the control group, the mean interval between flashes which would just produce a perceptible pupil response was 295 milliseconds (ms). The mean difference between right and left eyes was 8.84 ms. The mean difference between normal and abnormal eyes of the APD group was 78.6 ms. The difference between these results and those of the control group are highly significant statistically (p less than 0.001), and we conclude that this test may be of use in the assessment of defects of the afferent light pathways.