Ever felt nauseous or dizzy during a 3D movie? You're not alone. 3D makes most people sick and here's why.

"Are There Side Effects to Watching 3D Movies? A Prospective Crossover Observational Study on Visually Induced Motion Sickness" "The increasing popularity of commercial movies showing three dimensional (3D) images has raised concern about possible adverse side effects on viewers."

"Why Do 3-D Movies Make Some People Hurl?" "Nothing can ruin a good movie faster than the sudden feeling that you're about to throw up. But for many people, the images in 3-D or IMAX movies look so real that they mess up the brain's ability to sort out the signals coming in from the senses, and trigger that queasy feeling."

"Study: 3-D movies leave many feeling sick" "If you found yourself feeling a little woozy while watching 3-D films like "Avatar" or "Tron," you won't be surprised to hear this."