I watched the first 2 episodes of the 1960's BBC tv series of 'Day of the Triffids' tonight.
I do remember watching it when it first came out and I'd already read the book. It's still the best version, even though or maybe because it's so period now.
It has the painful kind of realism of 60's drama. The acting is wooden, but that also helps to make it feel like this awful thing is happening to ordinary, boring people. The sound effects help. I dunno if the BBC radiophonic workshop was involved , but I think it may well have been.
I shall be tuning in to get the next helping.
I have also seen the 1960's cinema version and the recent modern tv adaptation. I'm rather geeky about John Wyndham and John Christopher, they were my favourite SF writers in my teens.