Does any one else's iphone 4 appear to have a better viewing angle when viewed from the left side than the right? When viewing from the left at ~170-180 degrees, the screen appears crisp and vivid, but from the same angle from the right side, the screen is noticeably darker with a little bit of color inversion. Is this how all retina displays are or might I have a defect? I mean, the issue isn't too noticeable and not something that i'd get an exchange for, i'm just curious.