That would make sense. I hadn't considered the lack of eyelids.You know, I honestly have no idea. I'm trying to rack my brain and draw out all of the information I know about the autonomic nervous system, but it's no use. I think I was an expert on it for about two days, took an exam, and now I remember very little.
And to be honest, I don't even know if snakes utilize the same stress hormones as us.
I do think I've noticed it a few times, but I have a feeling it was light coming in. My snake got scared, moved, and happened to have light enter his eye when moving. I guess I could go scare him and see what happens, but that would be a little mean. lol.