Abstract: A Non-Maxwellian, free viewing system capable of psychophysical measurement of visual sensitivity for the determination of ocular components is disclosed. The apparatus features electronically controlled light emitting elements whose outputs are variable with respect to intensity and temporal pattern, and can be combined by a small number of optical components. The light emitting elements can have outputs of different wavelengths, can be positioned at different retinal locations, and can be viewed through masks or apertures having different geometries. These features permit miniaturization of the device, and eliminate a major or experimental difficulty of light path alignment associated with larger systems, thus simplifying the measurement of macular pigment density compared to procedures used with a full sized optical bench.