<prompt> Ishihara chas are used in diagnosis of which of the following?MyopiaHypermetropiaColour blindnessNone of the above  <response>: The most common test for color blindness uses the Ishihara chas, which are plates containing figures made up of colored spots on a background of similarly shaped colored spots. Ref: Ganongs Review of Medical Physiology 23rd edition, Chapter 12. 