Cracked headlight housing.

New to the sight, glad to find others with the same concerns.
I own a 2010 Toyota Tacoma, about a year ago one of the headlight housings had various vertical cracks in it. I thought it might be because of pebbles, birds or various other road debris. Suddenly I see the other headlight is doing the same thing and I know I have not hit anything in awhile. I know people who own older models of my truck that had a problem with their lights fogging up so the manufacturer changed the formula of the glass that is now used in the newer vehicles. Is this a defect others are experiencing and what is it that can be done to rectify the issue with Toyota, if any? I have had issues with other things and they always have an excuse as to not take the blame for defects in their trucks. Any response would be appreciated.