Looks like 3D is as safe as it gets. Just don't pop 3D glasses on your baby.
Alright, let's nip it in the bud now. 3D is safe. You're not going to get some kind of weird permanent eye damage because you wore 3D glasses. "There are people who get uncomfortable with it," says Dr. Mark Borchert, "but there's no evidence it can cause permanent harm to your vision."
Now, when it comes to your three year old, things are different. You see, the whole binocularity thing – seeing one image with both of your eyes – is something that has to be learned. According to Borchert, that happens within the first three years of your life. It's possible that 3D viewing could affect that process.
On the flip side, a three year old that hasn't yet fully developed his or her stereoscopic vision won't benefit from 3D anyway. In other words, they won't be watching movies or playing games in 3D anyway. "I can't imagine how this is going to cause any kind of permanent harm to someone who is over four years of age."