A method for noninvasive analysis of a retina includes exposing the retina to one or more first sets of at least three illumination light signals. The at least three illumination light signals each have a different wavelength. The method also includes optically collecting a reflected light signal for each of the at least three illumination light signals of the one or more first sets. Each of the reflected light signals is a portion of the respective illumination light signal reflected by the retina. The method further includes detecting the reflected light signals of the one or more first sets as a function of intensity. The method still further includes determining a first opsin density using the detected intensity of each of the reflected light signals of the one or more first sets.