The evilness of man for all and sundry to observe. This is not so much as a movie about mankind going blind either through an infection or a virus, or some strange and perverse mutation. Instead of seeing a void, the victims all experience blindness akin to "seeing" a bright light shining right into their eyes. How and what the cause was, is not the concern of this movie, directed by Fernando Meirelles.
Rather, it explores man's innate propensity to exploit others for selfish survival, and while intriguing to watch on screen how these episodes unfold, there are some starkly disturbing scenes that may not go down well with those who are meek of heart. You'll see how vile the evil intentions get, and good morals and principles get thrown out the window, as everyone grapples with the notion of sacrifice for the greater good. There're also some nice technical touches that Meirelles employs to put you into the shoes of the victims, and have to rely on ambient sound to tide you through, but used often enough, these turn out to be a one-trick pony that gets tired after a while.
Nonetheless this is still an engaging piece of work in exploring the deepest and darkest of the human psyche, so it is Recommended stuff, even though you have to persevere through the sagging middle section.