Hi Dan
I do not know about the side effects of Enbrel, and maybe the flashing has something to do with that drug, but I wanted to mention to you that this is something you might want to tell your physician or optometrist.
My husband had this happen to him (for an unrelated and then-undiagnosed eye problem) and it turned out that the flashing (like little fireworks when he closed his eyes) was the result of a partial detatchment of his retina. I am not a physician and hopefully this is not the case in your situation and and I certainly do not want to alarm you but in my husband's case, he prevented further visual problems by attending to the flashing.
Good luck.
Stephanie
