Obviously 3D can be seriously uncomfortable but I saw today on a BBC article that alot of parents are returning 3DS's because of them causing their children headaches. While i haven't bought one (yet) I did play street fighter on a demo model at a local gamestop and I had the same problem after about 15 seconds. Mind you I've played the entirety of killzone 3 and many hours of GT5 on my LG TV in 3d for hours and not had that problem. (adjusting that slider on the 3DS didnt help much) I'm not really up to date on the screen tech used on the 3DS but is it just naturely harder on the eyes without glass's or whats the deal?