I've tried sitting different positions, lowering brightness, and not even spending much time on it. However it never fails after about 15-20 minutes I start getting a headache that sometimes just will not go away for almost 24 hours. For some reason wearing polarized sunglasses seems to help, and I was wondering why I might be getting headaches and why the sunglasses seem to help.
I wear prescription eyeglasses already. Funny thing is I went five days without touching the iPad and not one headache. maybe it's as simple as I need a new prescription, but just hadn't renewed 2 years ago. I guess a lot can change in two years.