| Directions for COLORBLINDNESS TEST |
| How to use the Test The plates are designed to be appreciated correctly in a room, which is lit adequately by daylight. The introduction of direct sunlight or the use of electric light may produce some discrepancy in the results because of the alternation in the appearance of shades of color. When it is convenient only to use the electric light, it should be adjusted as far as possible to resemble the effect of natural daylight. The plates are held 75cm. From the subject and titled so that the plane of the paper is right angles to the line of vision. The numerals that are more then three seconds delay. It is not necessary in all cases to use the whole series of plates. Plates 12, 13 and 14 may be omitted if the test is designed merely to separate the color defectives from those with normal color appreciation. |