A portable,solid-state anomaloscope

Various methods of assessing color vision are discussed. The anomaloscope is concluded to be the best of these, but it is not widely used because of complexity and cost considerations. The design of a portable, solid-state anomaloscope that uses tristate light-emitting diodes is described. This device has many of the desirable features of the standard Nagel-type anomaloscope and can be constructed at a fraction of the price.