• Two hundred sixteen eyes (164 patients) were studied with the Arden printed contrast gratings to test Arden's hypothesis that an abnormal score would distinguish between eyes with and without glaucoma. Ninety-five eyes were normal and 75 eyes were glaucomatous; 46 eyes suspected of being glaucomatous were also studied to determine whether such eyes would score differently than eyes with normal intraocular pressures. No age-dependent trend in scoring was found in the different diagnostic categories, except with the age group younger than 40 years, which had consistently better contrast sensitivity. The tests were demonstrated to be reproducible over time and showed little or no intertester variability. Decreased contrast sensitivity was found in the glaucomatous eyes compared with normal eyes. The scores of the eyes suspected of being glaucomatous fell between the scores of the glaucomatous and normal eyes. Overlapping distributions among the three groups, however, limit the diagnostic value of the test.