Dvorine test


The Dvorine test is a set of pseudoisochromatic plates used to screen for color vision deficiency, devised by American optometrist Israel Dvorine during the 1940s. Early wartime editions appeared as Dvorine Color Perception Testing Charts, followed by ring-bound booklets titled Dvorine Pseudo-Isochromatic Plates.

History

During the Second World War, U.S. demand for color vision screening outstripped supplies of imported tests. Dvorine developed an American alternative using pseudoisochromatic designs, first published as the Color Perception Testing Charts. Subsequently, later editions were issued as Dvorine Pseudo-Isochromatic Plates and widely used in industrial, educational, military, and aviation settings in the United States.

Test design and editions

Dvorine’s plates are arranged into demonstration, screening, diagnostic, and non-numerical sub-sets. A commonly cited configuration describes a 24-plate edition in which plate 1 is a demonstration plate; plates 2–15 are used for screening; plates 16–17 differentiate protan versus deutan defects; and plates 18–24 employ shapes for examinees who cannot read numerals. A 16-plate edition has also been described with plates 2–9 for screening, plate 10 for protan/deutan differentiation, and plates 11–16 for illiterates. An NCBI Bookshelf entry lists a 1963 fourth printing by Harcourt, Brace and World containing 23 plates.

Administration and scoring

Like other pseudoisochromatic tests, performance depends on standardized viewing conditions. Experimental work has shown that the Dvorine and AOC plate tests are more sensitive than the Ishihara test to changes in viewing distance, duration, and illuminance, underscoring the need for strict test conditions.
Historically, U.S. aeromedical guidance has treated the Dvorine second edition as a 15-plate screening book for certain occupational contexts: for Air traffic controllers, FAA documentation lists failure as “more than 2 errors on plates 1–15.” FAA aeromedical research reports and protocols also refer to the “literate plates ” subset when using Dvorine in experimental settings.

Validity and comparisons

Comparative studies from the mid-20th century evaluated several pseudoisochromatic tests—including Dvorine—against each other and against other modalities. In an FAA field study relating clinical tests to performance with the aviation signal light gun, the Dvorine plates ranked among the better predictors of practical signaling performance. More recent military screening research reported that certain pseudoisochromatic plate tests performed comparably to an anomaloscope for sensitivity/specificity, while modern computerized tests also showed high diagnostic performance.

Current regulatory status

For pilot medical certification in the United States, the Federal Aviation Administration requires approved computer-based color vision screening tests for exams performed on and after 1 January 2025. The FAA’s 2025 ATCS guidance continues to list legacy plate-based instruments as acceptable for controller screening, alongside newer computerized options, with explicit pass/fail criteria stated for each test family.