Critical Flicker Frequencies with Red, Green and Yellow Lights in Congenital and Acquired Colour Vision Deficiencies

Abstract

The idea that the type and degree of colour vision deficiencies could be assessed easily by testing patients presenting congenital or acquired colour vision deficiencies with red, green and yellow flickering LEDs led the authors to conduct the following experiment. Using targets with the same luminance but of different colours (660 nm for red, 550 nm for green and 570 nm for yellow), and varying their frequency from 1 to 79 Hz, the authors were able to measure the critical flicker frequency for all patients. In addition, we conducted routine colour vision deficiency tests such as the Nagel anomaloscope type I, various pseudoisochromatic plates, the 100-hue test, the panel D-15, etc. The results of the various tests in subjects presenting congenital protan and deutan defects, subjects with acquired colour vision deficiencies by central serous chorioretinopathy or optic neuritis, and subjects with normal colour vision were then used to determine the usefulness of the critical flicker frequency testing method.