Physical characteristics and perceptual effects of "blue-blocking" lenses.

The transmission-optical properties of a "blue-blocking" lens and its influence on several aspects of human visual performance were assessed. Results showed that the lens was effective in absorbing ultraviolet and blue wavelengths and that its effects on contrast sensitivity and visual evoked potentials (VEP's) were similar to those produced by an equivalent neutral density (ND) filter. Although the lens did not alter stereopsis, it did produce severe color discrimination losses for normal and dichromatic subjects.