WarmWaterDiver:Damsel,
I have used Transitions lenses for some time now. They darken sufficiently, and darken / lighten much more rapidly than older Photo Gray tech, but when driving or riding in a vehicle the tinted / polarized safety glass keeps the lenses from darkening to the same degree of "darkness" you would obtain standing outside a vehicle - but they do take the edge off. Works pretty well for me.
very true, do to the way the transitions work, they are totally activated by UV rays. Most windshields have a uv filter built right into them, therefore, the lenses never get their darkest in a car. I wouldn't recommend the Transitions for a photophobic person, or someone with very light blue/green eyes (at least not for in the car)
now if they could only invent contact lenses that darken outdoors we'd all be set.... (eeek, get a visual on that one, someone walking up to you with their entire iris covered, freaky)