The index can only be seen after exposure to strong light, and for a few minutes only, with a fairly dim light emited.
But this is very normal, since half-life of tritium is 12 years, so after 40 years there is logically very few beta rays emited.
I agree with everybody that it is very odd not to have a fully luminescent dial on the remake, but I guess this will be corrected in another version (it has to be!)