From Hollywood studios to Japanese TV makers, powerful business interests are betting 3-D will be the future of entertainment, despite a major drawback: It makes millions of people uncomfortable or sick.

Optometrists say as many as one in four viewers have problems watching 3-D movies and TV, either because 3-D causes tiresome eyestrain or because the viewer has problems perceiving depth in real life. In the worst cases, 3-D makes people queasy, leaves them dizzy or gives them headaches. Get the full story »