Yes, it is. And best of all: it is rather easy to do. I used Bman's 3.04 mod and edited the sight range to this:
I made this because i saw no reason why in broad daylight aliens could see further than man, it's not that all humans are shortsighted
For the night i gave the Aliens a tiny advantage (maybe they have heatvision?
) but nothing big.
Works fine and looks much more realistic!
If you want i can send you the modified file, but it is really easy to change it yourself, simply follow Bmans tiny tutorial in the readme.