To The Tester

Quantitative measurement of colour vision is an important diagnostic test used to define the degree of hereditary colour vision defects found in screening with pseudoisochromatic tests and in evaluating deficient colour vision from acquired disorders.

The Quantitative Colour Vision Test, Panel 16, is unique from other quantitative colour vision tests because it uses large cap sizes, which gives more information about colour vision function both in normally sighted and visually impaired individuals.

The Panel 16 Colour Vision Test consists of a set of a "pilot" and 15 test caps of the same hues as in the Farnsworth Panel D-15 Test. The diameter of the stimulus area is 3.3 cm (1.3 in). The stimulus size can be reduced by using a dark gray restriction ring with an opening of 1.2 cm (.47 in) in diameter.

The large stimulus area corresponds to the visual angle of 3.8° when testing at 50 cm (20 in) and to 6.3° when testing at 30 cm (12 in). The small stimulus is seen as the recommended 1.5° stimulus at a distance of 46 cm (18 in). When testing young children or persons with low vision, the distance is often much shorter than 30 cm, thus the size of the large stimulus becomes 9.5° at 20 cm (8 in) and 19° at 10 cm (4 in).