Interesting and good to know! If it makes you feel better if they go into the "coop" half of our barn there is a wall that blocks most of the light from them.
I turn the barn light on and never turn it off until spring. It gets so bloody dark so early and I can't see them to feed them. So it's mostly on for me and them laying eggs is just a bonus. I suppose I could turn it off but it's in a far off corner that I store stuff in front of and I'm lazy so...