One week into its theatrical run, Monsters vs. Aliens has already become a certified, three-dimensional mega-blockbuster. In its opening weekend, the film crushed previous records by pulling in $33 million in revenue from RealD and IMAX screens and $59 million total; with little competition at the box office, there's every reason to think it will become the highest-grossing 3-D movie of all time. The timing couldn't be better for the evangelizing studio executives who plan to release 40 more films in the format over the next few years. At an industry trade show this week in Las Vegas, Fox studio Co-Chairman Jim Gianopulos called 3-D "the most exciting new exhibition technology since they put sprocket holes in celluloid." Jeffrey Katzenberg, whose DreamWorks Animation studio produced Monsters vs. Aliens, predicts that soon enough all movies will be made in 3-D and audience-members will bring their own pairs of polarized spectacles to the theater.
What about the failed 3-D experiments of the 1950s and 1980s? Those movies, say Katzenberg and the others, were beset by technical problems that gave viewers eyestrain, headaches, and nausea. (A Katzenbergian mantra: "Making your customers sick is not a recipe for success.") The problem has been solved, they claim: The latest batch of stereo flicks relies on a crisp and clean digital technology that's easier to watch and enjoy. "Comparing the 3-D of the past to this is like comparing a Razor scooter to a Ferrari," Katzenberg tells reporters. So far, reporters have seen no reason to doubt him—over the past few years, countless trend pieces have parroted the industry line on how "3-D's most egregious side effects" have been eliminated. The credulous messaging has become even more intense in recent weeks: Take Josh Quittner, whose March feature in Time toed the party line in the clearest terms imaginable: "As just about everyone knows," he dutifully explained, "old-school 3-D was less than awesome. Colors looked washed out. Some viewers got headaches. A few vomited." Now, with digital 3-D, Hollywood has found "a technology that's finally bringing a true third dimension to movies. Without giving you a headache."
Let me go on record with this now, while the 3-D bubble is still inflating: Katzenberg, Quittner, and all the rest of them are wrong about three-dimensional film—wrong, wrong, wrong. I've seen just about every narrative movie in the current 3-D crop, and every single one has caused me some degree of discomfort—ranging from minor eye soreness (Coraline) to intense nausea (My Bloody Valentine). The egregious side effects of stereo viewing may well have been diminished over the past few decades (wait, does anyone really remember how bad they were in 1983?) but they have not been eliminated. As much as it pains me to say this—I love 3-D, I really do—these films are unpleasant to watch.
That's because the much-touted digital technology is not fundamentally different from anything that's been used in the past. Today's films, like those of yore, are made by recording and projecting a separate pair of image-tracks for each eye. These are slightly offset from each other, giving what's called a binocular disparity cue, which in turn produces an illusion of depth. (It's the same idea as an old View-Master, or an even older stereoscope.) For at least the past 50 years, and across several theatrical revivals, 3-D filmmakers have used the same technique for separating the two tracks: They project the footage for each eye through lenses of different polarizations for an audience wearing polarized glasses with matching filters. (Despite frequent claims to the contrary, the 3-D films of yesteryear were rarely shown in anaglyph with those schlocky red-cyan glasses.) Whatever breakthroughs we've seen in 3-D technology have been relative refinements of the same technology. The essential mechanics of the medium—and its essential side effects—haven't changed at all.
Vision researchers have spent many years studying the discomfort associated with watching stereoscopic movies. Similar problems plague flight simulators, head-mounted virtual-reality displays, and many other applications of 3-D technology. There's even a standard means of assessing 3-D fatigue in the lab: The "simulator sickness questionnaire" rates subjects on their experience of 16 common symptoms—including fatigue, headache, eyestrain, nausea, blurred vision, sweating, and increased salivation. (Japanese scientists use a native term, shoboshobo, to describe the "bleary eyes" that sometimes afflict 3-D viewers.) Despite all this work, no one yet knows exactly what causes this visual fatigue, or "asthenopia"; in any case, there's little reason to think it can ever be overcome.
One potential explanation for the discomfort lies with the unnatural eye movements stereoscopy elicits from viewers. Outside of the 3-D movie theater, our eyes move in two distinct ways when we see something move toward us: First, our eyeballs rotate inward towards the nose (the closer the target comes, the more cross-eyed we get); second, we squeeze the lenses in our eyes to change their shape and keep the target in focus (as you would with a camera). Those two eye movements—called "vergence" and "accommodation"—are automatic in everyday life, and they go hand-in-hand.