COLOR VISION SPECIAL TESTS
100 Hue and Lantern Test
OVERVIEW: In addition to providing color vision assessment with Ishihara plates, the service provides Farnsworth AO HRR plates, D15, FM 100 hue testing and the “lantern test,” required by some occupations.
The Ishihara plates can be done in a short time and are available in most eye professionals’ offices. They mostly useful for detecting the type of red-green color confusion found in around 6% of males. Ishihara testing can also be abnormal in severe acquired color vision loss.
In addition to the above tests, our service provides the more definitive and sensitive testing with the D 15 panel, the 100 hue test. These tests help determine the character of the color abnormality and whether it is due to photoreceptor or optic nerve disease. AO-HRR plates are also available, which may be useful as a quick screening tool to identify blue-yellow color deficits.
We also provide the “LANTERN TEST,” which is a specific type of test required in some professional job applications typically related to operating aircraft, trains, or boats.
HOW DONE: In the 100 hue test and in its shorter version, the D 15 panel, the patient is asked to put in order of hue change a series of discs with colored inserts. The former takes about an hour and the latter about 15 minutes. Importantly, the test is performed under standard lighting conditions.
USEFUL FOR: The specialized tests help define the character and possible causes of the color abnormality. The sensitive FM-100 hue test is also important in following patients who are taking ethambutol for tuberculosis since acquired color vision loss is an early indicator of ethambutol toxicity.
HOW REPORTED: The D15 panel is reported as the axis along which most color matching errors were made thus distinguishing congenital from acquired defects and is presented in a display of a circle with 15 points along its circumference. The FM-100 hue test is reported in summary form as the score related to the numbers of errors made in matching and in the more detailed form as a page size disc with errors displayed in the axes in which they occurred.