Lenses for lamps can improve the quality of the light emitted through lens
by interacting with the light bulb. Photoluminescent dyes as well as
non-photoluminescent dyes may be incorporated into a polycarbonate lens
in order to shift the chromaticity of the light source. Further, design
features such as grooves or protrusions may be incorporated into the lens
to allow light produced by the photoluminescent material to escape the
lens and be added to the emitted beam to further shift the chromaticity.
The emitted beam is of a legal color and intensity as defined per the SAE
J578 and SAE J1383 standards. The lighting performance may also be
improved in such manner as reducing discomfort glare, increasing
brightness or producing a beam that enhances road visibility at night to
the human eye.