One of my headlight lens (Driver side) is letting water into the headlight....

then a few months later my other headlight is letting water in also....

But it evaporates a few days later....

Is my headlight system gonna get really damaged if i dont get them replaced/fixed, if they are fixable?

I noticed that when changing the bulbs, that the rubber ring inside of the cap, is very dry, and had white stuff on it that would not come off.... Do you think that it could be that? something else?-the 2nd one notiably started after I replaced a low beam bulb... But i have re-screwed the caps back in many times with the "lock" logo at the bottom point..

 

Unless water fills up to the electrical connections, I wouldn't worry about it as far as causing further problem. Unless you can test to find how it comes in, you can replace the rubber shield, given you can buy it separately.

Mine headlight casing is cracked with a hole, I just ignore it since I don't want to spend more money on this car unless if I have to.

 

I know that entire headlight assembly is like 700$ at the dealership..