From: James Propp <jpropp@cs.uml.edu>

While we're talking about optics, I was musing the other day about whether there's a way to make a windshield (or a pair of sunglasses) that will transmit less of the light emitted by really bright sources without transmitting less of the light emitted by dimmer sources.

i remember a spaceship windshield that had that ability, in some Larry Niven story. Remembering his style, but not the particular story, he probably had three paragraphs of patent-application- quality prose attached. Bug eyes sometimes have an apparent pupil that's really the subset of lenses looking at your eyes. Maybe something like e-ink cells, with floating directional light blockers that could be aimed. Maybe a fancy Fresnel lens could block light in a single direction (or vertical band) but could be mounted for aiming.

(I'm not talking about glare-reduction of the ordinary sort --- at least I don't think I am! --- since it's my impression that glare-reduction makes everything look dimmer.)

Vertically-polarized glasses selectively filter out specular reflections from horizontal surfaces. But, also more than half of other light, it's true. --Steve