Effect of Repeated Testing on Contrast Sensitivity

The effect of repeated testing on contrast sensitivity was examined across days and between eyes with the Nicolet CS‐2000 Vision Tester. Monocular contrast sensitivity functions (CSF's) were measured with the standard technique for training days 1 to 5 on a group of 20 subjects. The group was then divided into four groups of five subjects each. A single post‐training CSF was obtained for each group 1,3,5, or 7 days after the cessation of training. Results show that there is no measurable effect of practice on contrast sensitivity over a 5‐day training period, nor is there any decrease in performance in the absence of training. CSF's were also obtained on both eyes of a separate group of subjects. We found no transfer of learning either between eyes within a single session or across multiple training sessions. We conclude that although the absence of a significant practice effect has important clinical advantages, the variability of the technique is high, allowing only robust experimental effects to be detected.