Years ago, I toured a Timkin bearing manufacturing location in RIDC industrial park in Blawnox Pennsylvania (N.E. from Pittsburgh). Inside that big warehouse like building they had a decent size room in the middle of the huge building. That room was insulated and had it's own heating and AC system. The lights inside it were dim, and the temperature was kept within a narrow range. It was the room where they measured the bearings and races they made, and it also had some manufacturing equipment for making some small tight tolerance bearings and races, and some bearing assembly equipment.
In other words, they even take into consideration the temperature of the bearing or race and the measurement equiptment when they check if it is within specifications. And bright light may interfere so the lights were dim.