There's obviously a range of opinions expressed above - some informed some not so much.
Here's my $.02 on the subject:
1) Tritium sights do allow you to use the sights effectively enough for combat accuracy in low light conditions. Obviously you need enough light to still see the target against the background. As long as you have enough light for that you can put the the tritium front sight on target. *IF* you've learned to shoot properly and *mastered* the basics of sight alignment, grip and trigger control to the point that you can bring the pistol up to eye level with the front sight on target and have the rear sights be aligned (due to repetition and muscle memory), then putting the front sight on target is sufficient as your grip will naturally take care of the rear sight alignment. This means that once you are proficient you can also use a tritium lamp in the front sight on a fixed sight revolver that won't accomodate a tritium rear sight.
2) In regard to all of #1, I've probably met a dozen law enforcement officers over the years who both learned properly and shoot enough for that to happen. Most LEOs are not gun people and don't shoot much more than required to qualify. That lack of mastery is a huge part of the abysmally low hit rates for officer involved shoots, even in good lighting conditions. They get even worse in low light.
3) Fiber optic sights are totally useless at night. At best they extend the time the front, and when applicable the rear, sight can be seen around dawn or dusk. Great for hunters, useless to everyone else.
4) All black front and rear sights give a superior sight picture in good light where you get high contrast between the light buff or white background and the black bullseye and sight elements.
The good news is that you can use a black sharpie to put a thin layer of black ink over the tritium lamp and get the black front and rear sight picture during the day and still see the tritium dots in low light.
5) Tritium sights also work well with a properly used tactical light. It will allow you to point the pistol and keep the sights aligned and on target, until you use a momentary switch on the light to quickly flash the target to confirm it's an intruder who needs shot, rather than, for example, your teenage kid sneaking home late at night.
It's worth noting here that how armed citizens use a light is different than how LEOs will use a light. LEOs go in dark places looking for bad guys because they have to. They also don't have the home court advantages of knowing the layout and where everything is at.
They also don't have any night adaptation given they've been driving, been around streetlights and have been using those way too over the top stupidly bright flashing lights on the lightbars. Over the years they've gone way to far and they are so bright that they are a hazard to both other drivers and to officers when those officers have to then go into a dimly lit space.
That means officers really need flash lights that are continuously on, while armed citizens should be preserving the advantage of their night adapted eyes until they need to shoot.
6) Someone commented that an SF person who trains law enforcement regards tritium sites as useless. Well...you need to consider the source. Night vision, and in particular Gen III or better is the norm in US military service, so in that context there isn't much need for tritium.
It also begs the question of the overall utility and wisdom of using an SF operator to train law enforcement. 90% of the problems people are protesting today trace back to the "warrior cop" ethos and training officers to use military tactics.
Time, distance, cover and use of common sense and officer discretion when appropriate go a lot farther in achieving both greater public service and greater officer safety and in the long run than training police officers to be "operators".
