We had a power blackout earlier on tonight (good ol' australian efficiency.... ) so i ended up playing piano for a good 2 hours. By the end of the first hour, I could barely see the keys... and by the 2nd hour, I couldn't see a thing. Having said that, I played pretty well considering. I also sometimes play without my glasses, and seeing as I am VERY short sighted, it helps me relax. But I can play completely blindfolded (I've been tested on that believe it or not) which is pretty good. Very calming.