The invention relates to a method for designing color filters which improve or modify color vision of the human eye. According to the invention a desired opponent signal function to be attained is divided by a real opponent signal function characteristic of the eye color vision to be improved or modified, the negative range of the resulting function is replaced by zero, the whole function is normalized to give a spectral transmission function, and, if desired, one or more section(s) of this spectral transmission function is modified. The invention also relates to color filter means designed by the above method.