Glaucoma suspect eyes were seen during a five-year study on color visual fields that used a 440-nm test on a bright-yellow background (96 normal eyes, 55 suspect eyes, and 110 eyes that developed glaucoma). The predictive ability of the test was assessed in 25 eyes followed up for more than one year, five of which developed glaucoma. These five eyes and those at high risk showed higher mean defect (P < .0001) and number of defective points (P < .0001) than the other suspect groups, which were not significantly different from normal eyes. The mean defects (± standard deviations) and average number of defective points were 1.4 ± 2.3 dB with 8.9 points (low- risk eyes), 1.1 ± 1.2 dB with 8.0 points (medium-risk eyes), 6.7 ± 2.8 dB with 27.7 points (high-risk eyes), and 9.3 ± 1.8 dB with 39.4 points (eyes that developed glaucoma). Normal eyes had an average of 3.4 defective points. These results were similar when all 55 suspect eyes were analyzed. Color visual fields identify early functional loss in eyes at greatest risk for primary open-angle glaucoma.