Apples and oranges.
The Tritium sights are made to be visible in the dark.
The fiber optics are made to be highly visible in the sun, but do nothing at all in the dark.
Tritium night sights appear as fairly normal white dot sights in daylight.
Then glow green, orange, or yellow in the dim darkness when the goblins come out.
Meproite & Trijicon night sights are guaranteed to glow for 12 years.
TruGlo for five, maybe.
rc