Blindness?

The book details it better. Spoilers to come:

Wyndham was superb at suggestion. What starts as a general assumption - i.e., the green meteors blinded most of humanity - is questioned toward the end of the book, whose protagonist reminds his wife that just before the blindness, the triffids and the fall of civlization, there were all kinds of terrible man-made things constantly in orbit around the earth. He suggests that maybe the meteor swarm was not meteoric at all, but a satellite attack or experiment gone horribly wrong. His wife replies, "but that would be...diabolical", to which hubby replies that it would be no more diabolical than any other super-weapon humans had developed up until that time. So Wyndham introduces the nasty suggestion - not a certainty, only a suggestion - that the near-universal blindness was actually caused by humans themselves, with the triffids taking opportunistic advantage of blinded prey, a theme which also dovetails with the novel's presentation of triffids as human creations, especially developed, possibly in Russia, for their incredible plant oils which revolutionized mechanized industry. Triffids, far from having "come on the meteors", were carefully developed and globally farmed. Their seeds would germinate and it was not unusual for people to find a triffid growing in some unattended section of their back gardens. Some people would have the plant's sting removed and keep it as an amusing pet - a walking, "talking" plant.

The novel does show a gradual but quick onset of the blindness, e.g., the protagonist, wandering through London, sees abandoned cars, but the cars have been pulled up against curbs and apparently braked/stopped in a more or less orderly manner. People's vision began to fail, but the process was just slow enough to permit most of them to safely park their vehicles without mass crashes.

The "meteor" shower was global, i.e., it followed night's progress across the planet, so that all that was required for near-universal blindness was people looking at the shower, which of course was guaranteed when media reports started blaring about "this spectacular natural event". The only people who escaped were those in prison, in submarines, those who worked night shifts and couldn't come outside to watch, or in the case of the female protagonist, were partying very hard or were ill and missed the shower, only to awaken to friends, family, and world gone blind.