My then 23 month old did not like the 3d movies (Muppets, Philharmagic and we didnt even attempt Bugs Life). He did fine until the physical effects occurred (water spray, air puff, etc). After that it was all over, even with the glasses off. After the first effect, he seemed to recover and tried to grab at the screen, but the next one would be it. I guess he realized he couldnt "trust" the movie at that point. It took a few months to get him over his fear of the dark too after that (he never was afraid of the dark and even now it doesnt bother him). I dont know if we will try again in Jan or not. He did see a 3d movie at the zoo. He tried to grab the screen and looked away a few times, but showed no trauma afterwards. Id say go ahead and try one, but sit near the exit in case you have to get out of there in a hurry. Thankfully the movie was loud enough and I could barely hear my son crying.
alison