An outstanding desideratum in ophthalmology, industry, and vocational schools is a simple, easily administered, unlearnable test which will reliably "screen," ie, separate, subjects with defective color vision from those with normal color vision. If such a test can be made qualitative (can diagnose the type) and also quantitative (can yield an estimate of the extent of the defect—mild, medium, strong), its value will be greatly enhanced. We think this can be done. At the same time, we believe that all candidates classified as defective should be subject to the further study with several different tests.
A look at the past.... Arch Ophthalmol. 2000;118(2):205. doi:10.1001/archopht.118.2.205