Director Fernando Meirelles is fascinated with travelers feeling their way through foreign worlds, such as City of God’s Brazilian favelas or The Constant Gardener’s Kenyan shantytowns.

Meirelles does the same in Blindness, a beautifully filmed, brutally wrought social thriller with a dash of science-fiction. Only here, protagonists literally stumble through a nameless city’s trash-riddled streets and hospital hallways smudged with feces. All but one of them is blind.

Based on a stream-of-consciousness-style novel by Jose Saramago, Blindness is a tale of profane punishment and sacred absolution. Always grueling and occasionally rewarding, it replaces Meirelles’ usually heated human emotion with cold, clinical case-study detachment; characters have no names aside from occupations or descriptions.

While repetitive, the film has courage to cast aside compromise and Meirelles gets easily the finest work in more than a decade out of the overrated Julianne Moore.

The film wastes little time establishing its conceit. A man is stricken by white blindness (“like swimming through milk”) while sitting at a traffic light. It’s a painless, but profound, phenomenon. He can’t see a thing.

One man offers to drive him home, which he does … right before stealing his car. Soon, it’s a Patient Zero situation: the man’s wife; the thief; arresting officers; Patient Zero’s doctor (Mark Ruffalo). Each is infected and contagious.

Meirelles peppers these scenes with some dazzlingly screwy sensory disorientation of his own – shimmering reflections in glass, a Vertigo homage in an examination room, sudden flashes of light, superimposed sights in a rearview mirror.

However, there is one person seemingly immune to what becomes a global pandemic – the doctor’s wife (Moore). Nevertheless, she lies to accompany her husband to a hospital where the blind are quarantined and abandoned.

If you can buy mass blindness, then you must also buy that those affected would be left to fend for themselves. After all, when has a government done that before in a time of crisis?

The blind are left to their own defenses, or, more appropriately, defenselessness. In the kingdom of the blind, the woman with two eyes is definitely not the queen.

That would be King of Ward 3 (Gael Garcia Bernal), a power-hungry man with a squalid soul who hoards food and trades it first for jewelry, then for flesh. A group sexual-assault sequence will be, for some audiences, the point of no return.

The chips aren’t down. They’re gone, and like most parables for how humans react, Blindness quickly devolves into showing the basest forms of human survival. Moore, Ruffalo and other characters (such as those played by co-stars Danny Glover and Alice Braga) realize futility in assigning order to chaos. It’s the macabre mood of The Mist on steroids.

What is thankfully toned down are Moore’s usual histrionics. Meirelles establishes early, and with simplicity, the power struggle between her and her husband, then uses the plague as a propellant to shift that power’s balance.

Wisely, Moore doesn’t play it as “I’ll show them” heroism. She’s a woman coping with the pain of seeing her status as caregiver become secondary to that as a wife and the resultant emotional infidelity. Using slow-burn anger and gradual development as a leader, Moore offers a remarkably restrained performance.

Yes, it’s disappointing that Meirelles doesn’t play to his empathetic strengths. At least he’s tapped into a skill set Moore rarely uses. In doing so, the duo provides Blindness what little hope for humanity it shows, and needs.