A few days ago I had a line of darkened pixels appear on my screen, at first I thought it was a scratch, but it's very smooth, and the color is always a very light grey. It's only strongly visible from a certain angle (which unfortunately is straight on, or the viewing angle I always use. I bought my MBP last summer, it's well kept for and I did not put any physical pressure or force on the screen, it just appeared over the course of several days (hours?). I tried running a dead pixel fixer with no success, I don't even know if they're dead pixels though. What should I do? Can I bring this to the apple store, do I need an appointment if I want to do this?