I've never heard of Triffids, so I had to go look it up.

Plot Summary for
Day of the Triffids, The (1962)



A shower of meteorites produces a glow that blinds anyone that looks at it. As it was such a beautiful sight, most people were watching, and as a consequence, 99% of the population go blind. This chaos results in the escape of some Triffids: experimental plants that are capable of moving themselves around and attacking people.