I know this is odd seeing me post, considering that I just posted a new thread about my mother-in-law possibly dying tonight--yes it still hurts and I'm still sad, but I also saw Avatar Sunday with my nephew. The odd thing is that I'm 48 and loved the 3-d effects. In fact I was extremely impressed since they use polarization technology rather than different colored lenses, so the colors looked normal for both of my eyes. My nephew, on the other hand, despite the fact he's 19 and plays lots of first-person shooter games on his X-Box 360, got all cross-eyed and a bit disoriented with a slight headache. He said his vision was a bit distorted for a short time, but was back to normal in about 15 minutes. The only effect I felt was I got rather sleepy for an hour after I drove home and closed my eyes for a bit, then, without actually falling asleep, felt a lot better and resumed normal activities for the evening. I was woken up early that morning so that could have been the reason for the sleepiness, too.
I think if the Transformers movies were 3d I would have been overwhelmed, but the upcoming Shrek III 3-D movie should be just fine--the previews shown looked quite bearable and didn't tax my senses at all. My own heart rate stays between 70 and 80 resting, and I don't believe it went up at all while I was watching "Avatar." I thought the movie was great, except for the foul language the Hollywood for some obscure reason thinks people want to hear in this and lots of other movies all of the time. The foul language alone is the only reason why I won't take my kids to see "Avatar." Get a clue, Hollywood! Drop the "colorful" language and you'll make a lot more money!
Chris