Visual bug (Turok)

vobscheem in essence,just yesterday established the Turk(can't remember whose repak) found such a strange bug,after the lab when we meet for the first time of the t Rex(and I need to run away from it) and that's how we go into the cave and leaving the cave I noticed a small translucent strip and the most interesting in the early game it was not but how to exit the cave(where we take the shotgun) it is possible to notice this band,it is thin and when you turn the camera its especially noticeable on the background of a tree or the sky,somebody faced with similar,what could it be?(Windows 10,Gtx 560 ti)