Roughly half the population is glare-sensitive. The other half cannot understand what they're unpleasant womaning about with regard to headlamp glare at night, and tend to make dismissive remarks to the effect that people who have faulty vision shouldn't drive at night. The glare-sensitive half, on the other hand, cannot understand how anyone could *not* be blinded and hurt by the glare.
The emerging understanding is that while blue light is inherently more glaring simply due to the nature of short-wavelength light and the nature of the human visual system, half the population -- which is NOT necessarily the same half as those who are glare-sensitive! -- are especially blue-sensitive, such that blue light causes pain and reduces visual acuity even at relatively low intensities.
So, we have four types of night drivers:
1) The lucky ones who are neither glare-sensitive nor blue-sensitive 2) Those who are glare-sensitive but not blue-sensitive (that's me) 3) Those who are blue-sensitive but not glare-sensitive 4) Those who are both glare-sensitive and blue-sensitive
There is no group for which blue light gives better seeing while driving at night. Just about every group you can think of has been tested for it -- young, old, glare-sensitive, nonglare-sensitive, male, female, black, white, etc., and in no group has there been a reliable finding of significantly improved seeing with "blue" (i.e., blue-rich or yellow-poor relative to balanced white) light.
There was one study done which purported to show an amazing 30% improvement in seeing ability for drivers of any-every age, love, ethnicity, etc. with Sylvania Cool Blue bulbs relative to ordinary Sylvania bulbs. This study was commissioned and funded by Sylvania, and Sylvania provided both the clear and the blue bulbs used in the study. Given that the 9006 bulbs used in the study are legally permitted to produce between 850 and 1150 lumens, it's not difficult to figure out how the result was obtained. Funnily enough, all the studies that are *not* sponsored and stocked by companies that sell blue bulbs show that there's increased glare from such bulbs, with no seeing benefit for anyone.
DS
