Nobel Prize winner José Saramago’s 1995 novel Blindness works on a number of levels. The story of a pandemic of blindness which brings down civilization, it can be seen as an AIDS allegory, or a metaphor for the ways in which even sighted people fail to truly “see” one another. And even though it was written years before 9/11, Blindness can also be viewed as a critique of government and individual responses to crisis situations.

This is heavyweight material, the kind that is not easily transferred to the screen, even in the hands of a gifted director like Fernando Meirelles. Allegory is hard to visualize, and even though the film version of Saramago’s book is a meticulously thought-out, occasionally startling piece of work, it fails to convey the frighteningly surreal nature of the source material.

The movie, like the novel, begins when a driver on a city street (Yusuke Iseya) is suddenly struck blind. Taken home by a Good Samaritan (Don McKellar) who then proceeds to steal his car, the driver and his wife head straight to an ophthalmologist (Mark Ruffalo), who can find no organic reason for the sudden attack of sightlessness.

Soon, however, people all over the city begin losing their sight, including the eye doctor. The government’s response is to quarantine the afflicted until a cure can be found, and when the eye doctor is taken away, his sighted wife (Julianne Moore) decides to go with him.

The blind are taken to an abandoned mental asylum, where they are locked in, provided with food, and told to fend for themselves. Terrified that the blindness is some sort of infectious disease, soldiers guarding the facility declare they will shoot any sightless person who gets too close, and even refuse medical help to a desperately ill man.

Things start to deteriorate quickly. Toilets back up, and the internees begin living in filth. Food shipments are delayed, or cut back. Then a group of male prisoners, led by a man (Gael Garcia Bernal) who has managed to smuggle in a gun, declare that they will control all the food rationing, and that in order to eat, the blind must give up their valuables. When no more bling is forthcoming, the leader demands women for his men. This leads to a nightmarishly shot orgy which is as terrifying as anything in the film.

From this low point, things begin to get better. The blind manage to escape from detention and wander back onto trash-strewn city streets down which sightless hordes stagger in their search for food and shelter. A group led by the doctor and his wife manage to find the ophthalmologist’s apartment, where they clean themselves up, eat heartily, and make plans for the future. Then a miracle of sorts occurs, and the film ends on a hopeful, but still ambiguous, note.

Everything about Blindness has been chosen with care, from the São Paulo and Montevideo locations, to the ferociously fine cast (Moore is particularly compelling as the only sighted person). Meirelles even uses white-outs throughout to try to give a sense of what the blind, all of whom claim they feel as if they’re peering through a milky sea, are encountering.

Yet the film feels fractured. The first part, as society attempts to deal with the plague, is rushed. The central section, inside the detention center, is compelling, realistic and awful to contemplate. But the last 20 minutes or so, after the blind escape, has the unfortunate look of a post-apocalyptic sci-fi movie. And one scene, in which Moore tries to escape from a market with bags full of groceries as blind scavengers lunge at her, seems to be influenced by none other than a George A. Romero zombie opus.

It’s been said before, and we’ll say it again: Nuanced literary works are simply not that easy to transfer to the screen. And works of an allegorical or metaphorical nature are even tougher. They tend to become literal-minded, even heavy-handed, when visualized.

Blindness doesn’t suffer those fates, but as well-made as it is, it still plays like a Cliff’s Notes version of a much more complex work.