Most people don't behave all that well in a crisis, according to Fernando Meirelles in his new film, Blindness. Jam them together in a small space under extreme duress, and they will revert to their most primitive instincts.

The film, based on a 1995 novel by Portuguese Nobel Prize winner José Saramago, sets up an extreme test condition and then runs its nameless--hence universal--characters through their paces to see who degenerates and who clings to a shred of decency. The premise resembles a traditional horror or sci-fi movie--an unexplained plague scythes through modern civilization--but the intent is more psychological than apocalyptic. The plague happens to be a peculiar form of blindness, one that leaves people lost in a sea of milky whiteness instead of pitch blackness. It could have easily been zombie-ism (the 28 Days franchise), a natural toxin (a la The Happening) or drifting radiation from a nuclear explosion (take your pick of 1950s sci-fi cautionary tales).

On the streets of an unidentified metropolis, people start losing their sight, with no explanation. The initial concern that the blindness is contagious seems like an excess of paranoia. In the first of many metaphors that Meirelles throws against the screen hoping that one will stick, he echoes the irrational fear of people with AIDS.

As we gather up a band of the afflicted, however, it appears that they have indeed been rendered sightless by serial contact. The first victim (Yusuke Iseya) has his car robbed by a faux Good Samaritan (Don McKellar, who also wrote the script), who then whites out. After the first man visits the eye doctor, the attending ophthalmologist (Mark Ruffalo) succumbs, which is a nice touch of irony that makes him the eye doctor who can't heal himself. His receptionist and two patients (one of them being Alice Braga) follow. Only the doctor's wife (Julianne Moore) keeps her vision, for reasons unknown. When the government starts trucking the blind to quarantine camps, Moore's character feigns blindness in order to stay with her husband. The camp is really a prison where even the guards won't patrol--they stay outside the walls at a safe distance. The occupants are fed, and that's it. A droning voice on a TV monitor assures them that all steps for their welfare are being taken.

In a parody of society's bureaucratic urge, the various wards elect representatives and attempt to govern humanely. Ruffalo's doctor plays the well-meaning liberal in this metaphor. Unfortunately, baser patterns quickly surface. The thief starts sowing discord (McKellar, who was very funny as an egotistical director on the Canadian series Slings & Arrows, pushes his semilovable creep too far into Kevin Pollak territory).

He's just a taste of what's to come when a genuine bad guy (Gael García Bernal having a high old time) and his criminal cronies use violence to hoard the dwindling food supplies. Somehow commandeering a gun (where did that come from? the film falters on details like this), García Bernal's character declares himself "The King of Ward Three" and starts demanding tribute from the other prisoners, even ordering them to send in their women to be raped. At this point, the film descends into a real hell where some viewers might not want to follow.

After so much despair, Meirelles then releases his core characters, allowing them to search for redemption outside the prison. To say any more would run the risk of making this review as overlong as the movie itself, which starts to unravel in the last half-hour.

Moore gives a solid performance, evincing terrific sinew as she slowly becomes the de facto sighted leader of her dependent charges. Too bad then that Danny Glover has to play that all-too-familiar character the beneficent old black man; even worse, in one very miscalculated scene, Glover's character recites, as if reading a satirical fairy tale, the government's doomed-to-fail efforts to cope with the epidemic. Ultimately, Meirelles wants us to believe that our individual natures can be bent but not broken. The good sink low but come to rest on a solid strata, while the bad have no internal barriers to stop them from plunging all the way to the bottom. The point is reinforced by one of the rapacious characters, who was blind from birth and uses his heightened sensory skills in all the wrong ways. "How could you? You're supposed to have empathy and human decency," Ruffalo shouts at him in high dudgeon.

Everything Meirelles and McKellar want us to take away from Blindness can be found in more modest, less visually adept genre movies. Twenty years ago, this could have been a great John Carpenter vehicle.

BLINDNESS (R; 120 min.), directed by Fernando Meirelles, written by Don McKellar, based on the novel by José Saramago, photographed by César Charlone and starring Julianne Moore and Mark Ruffalo, opens Friday at the Nickelodeon in Santa Cruz and Green Valley Cinema in Watsonville.

Send a letter to the editor about this story.