I have a retina MacBook Pro 15". I always assumed that it has a glass screen - it says so on Apple's website, and my previous 17" MacBook Pro also had a glass screen. Yesterday I got it to my Apple service provider to replace the display for some pixels that are stuck on bright - there's about 5 different spots and some of them have more than 1 pixel, so no problem, they agreed to replace it. But when they were cleaning the screen I noticed something stuck on the screen, like a tiny piece of dirt. Tried to get it off to no avail - and it feels like a little ding?! Now how is that possible, a ding on a glass screen - glass doesn't ding or scratch (well - easily), it breaks or it's perfect. So I started scrubbing - now since I am getting the screen replaced anyway I did something I wouldn't normally do and tried to clean it with the rough side of a 3M sponge - the kind that will scratch plastics and soft materials. Now I got scratches on top of the ding, and it's definitely confirmed that this is a ding not some very stubborn dirt! So I suspect that the retina MacBook Pro actually has a plastic screen. Glass does not scratch, certainly not with the rough side of a sponge - I use this sponge to clean dishes and glasses every day and they don't get scratched. I can use this on a window all day long and there are no scratches - it's just not hard enough. Or is the screen some sort of special extra-soft glass? My previous MacBook Pro 17 got scrubbed furiously and the screen always looked perfect, even 3 years later. That was a real glass screen, and I much enjoyed being able to clean it without worry. Seems like the retina MacBook Pro screen isn't quite that good.