As soon as this occurs the player models become brown and indistinguishable. This basically puts the nail in the coffin as far as online play is concerned as most multiplayer games use red and blue teams. This was quite off putting. Quake 3's already dark nature combined with the glasses' darkening effect did not lend to a pleasant experience. If you can put up with the darkened and murky colors, the effect is nothing short of quite stunning.
Objects seem to jut out of the screen, weapons seem to stick out menacingly.
The 3D effect is orchestrated quite nicely except for the 2D sprites used in video games like muzzle flashes and cross hairs everything appears fine. This did not really help me as it seemed to not actually point to where I was shooting. This option was best left turned off as I found it a distraction. The 3D effect seemed quite strange at first as objects seemed to jut out of the screen far too much, but as I got used to it I could perceive depth better and the jutting out all became relevant. It was decent, but the screen seems to be interlaced and the bands of black get distracting at any resolution less than 1024x768.