By accident I used a flashlight on my iPad Air and noticed a vertical bar about 1/2" thick from top to bottom that can only been seen with a light and when the iPad Air is turned off. It's just to the left of the home button. I'm just wondering if this is normal? It doesn't affect the iPad when in use. Is this just the technology of the screen? I hadn't noticed it until today. Of course I'm somewhat OCD and now that I've seen it, I would like to know what it is. Any help would be appreciated. Thanks!