Normative data for the standard pseudoisochromatic plates--Part 2.

The Standard Pseudoisochromatic Plates--Part 2 are designed as a screening test for acquired color vision deficiencies. In order to control for age-related changes in color vision, it is necessary to establish norms for this test. Results from this study suggest that, disregarding one figure on the first test plate, one or more blue-yellow errors indicate a blue-yellow color vision defect for patients between 20 and 60 years, whereas two or more blue-yellow errors are indicative of a blue-yellow color vision defect for patients under 20 years and over 60 years. For modified red-green test figures, one or more errors are suggestive of a red-green defect for patients under 60 years, whereas two or more errors indicate red-green vision defect for patients over 60 years. Asking patients to judge which figure is more distinct on each test plate is not useful in comparing responses between patients.