A nice chunk is missing out of that light! Some water intrusion as well, which is not all that uncommon with these lights. Under the right circumstances these things collect water like you wouldn't believe. You think they would've put drip holes in the door to let water drip out before it got to the optical assembly but I guess it never crossed their mind... Some M-250R2s (depending when they were made) collect water too. Sometimes Cooper lights manage too as well and those HAVE drip holes!

I've come across so may of these fixtures filled with water when we work on these things. it gets real nasty in these when the birds live in them and they are filled with water. The ones that filled the most were the ones that were installed tilting down. I'm almost thinking of maybe drilling small weep holes in these next time I go to one.

Yeah the water gets in when the mast arm is droopy or the light is tilted down. Yeah drilling a couple 1/4" holes in the door at the lowest part should prevent water from building up. With NGrid, they tend to replace the refractor with an FCO glass, which prevents the water from building up in the optical assembly but does nothing to solve the actual problem lol.