A meteorite shower that blinds 98% of the Earth's population is only a warm-up for the coming apocalypse: aggressive (and mobile) carnivorous plants take over the planet, giving new meaning to the term Persistent Vegetative State. One by one, survivors find each other and begin banding together, etcetera, etcetera. John Wyndham's original novel is one of those prescient, perpetually allegorical, perfectly eerie tales of SF armageddon, ranking with Matheson's I Am Legend, Finney's Invasion of the Body Snatchers, King's The Mist and of course War of the Worlds by some dude whose name I forget. Those stories pivot not so much on the weird disaster element -- be it vampires or space pods or extradimensional creatures -- but on how the surviving humans react and fight back against their hostile new environment.
Steve Sekely's 1962 film does Wyndham a disservice by lifting only the highbrow concept (Killer Plants! From Space!!) and ignoring the characters who actually powered the novel in the first place: their frustrated attempts at rebuilding civilization while on the run, sometimes losing each other along the way, spiced the original tale with drama aplenty. In the film, everyone is scattered from the get-go, and stays that way. The lead character is teamed with a little girl whom he protects, rather than a potential love interest with whom he can hook up in order to repopulate the planet (is he supposed to wait for her to grow up? --because that's just creepy). Another couple are holed up in a lighthouse for no good reason; he's a belligerent drunkard, she yelps a lot, I set a timer to see how long it would take for the plants to shut them both up. Since the predicaments aren't especially interesting, Sekely relies on the venomous, flesh-eating plants for terror, but mainly they just show up and shake their fronds and rarely eat (or even hurt) anyone that we see or care about. In the final accounting, Danny Boyle's Triffid-free 28 Days Later (2002) is actually a closer adaptation of Wyndham's story.