The Vistech Contrast Sensitivity Function tester (VCTS 6500-1) for distance was evaluated to determine the minimum age of children who could complete the test and to determine changes in the CSF as a function of age. A total of 72 normal children between the ages of 24 and 84 months were tested twice with each eye. The results revealed that no child below 36 months of age could complete the test and by 48 months of age 50% could complete the test. By 60 months all children could complete the test. It was also found that age increased the CSF increased equally at all spatial frequencies. A comparison between the eyes of the CSFs revealed a highly statistically significant correlation of 0.78, which showed that the eyes were very similar. Test-retest correlations (0.78) also were highly statistically significant, which demonstrated that the test was very reliable. The results are discussed within the context of screening young children for visual disorders and the evaluation of patching therapy for amblyopia.