I noticed that the sun glare looks different in 1PP vs 3PP. I was running on the road west out of Novo with the sun about to set below the trees on the ridge to the west, I swapped to 1PP to get ready to snap screenshots and noticed that the sun glare around the sun disappeared, instead there was just the misty haze around the sun. Swapping back and forth made the glare come back and disappear again, so it is definitely something that depends on the player perspective. When aiming down sight it is visible even when you are set for 1PP.

I uploaded a video where I'm messing about a bit to show how it behaved. I have not yet tried to reproduce.

Tagging it as minor since it is not crashing the game or anything, but considering many players are playing 1PP only they are really missing out on some of the eye candy if this is a common issue!