Refined flicker photometry technique to measure ocular lens density.

Many physiological and pathological conditions are associated with a change in the crystalline lens transmittance. Estimates of lens opacification, however, generally rely on subjective rather than objective measures in clinical practice. The goal of our study was to develop an improved psychophysical heterochromatic flicker photometry technique combined with existing mathematical models to evaluate the spectral transmittance of the human ocular media noninvasively. Our results show that it is possible to accurately estimate ocular media density in vivo in humans. Potential applications of our approach include basic research and clinical settings on visual and nonimage-forming visual systems.