The blurry/fuzzy movements kind of make it hard on the eyes after a few minutes of playing, and I have gotten headaches before, probably because 3D is such a new experience for me that I'm not used to it. All those fuzzy movements, etc. Matter of fact I always have the 3D effects turned off all the time, especially when playing right before bed. Sometimes I wonder why I didn't get the 2DS instead. But I never have the 3D feature on. I especially won't have it on when we're on the road for the same reasons. Side affects could probably be worse while travelling.