light having a tinge of yellow represented by approximately 540 nanometers is less distinguishable than light which has a tinge of yellow and is then mixed with blue the central beam pattern produced by the opaque coated bulb as shown in fig5 provides substantially white light in the center portion thereof where the outer edges thereof will be tinged yellow on the blue coated bulb as shown in fig4 blue light is mixed with this yellow tinge which produces a slightly blue green color which yields better color differentiation tests have indicated that color identification using the blue coated bulb is better by approximately 30 to 35 over the black coated bulb however as stated above the primary purpose of the opaque coating as taught in the present invention is to reduce glare and provide a more acutely defined beam pattern which can be played on the roadway immediately ahead of the vehicle referring now to fig7 a second embodiment of the bulb is identified by reference character 32 in which the outer peripheral opaque coating 34 and the central opaque coating 36 is circular in shape thereby providing an annular clear aperture 38 naturally the circular pattern may be considered as a special case of ellipse in which the eccentricity is zero it should be noted that other lenses than those described herein may require the peripheral and central coating to take on shapes different from the elliptical and circular shapes described and can best be determined by optical testing from the foregoing it is apparent that the present invention provides a lamp which is particularly designed to produce an acute beam pattern and wherein the peripheral illumination or incident light has been greatly curtailed which results in reduced glare in adverse visibility conditions whereas the.