The Watchismo Times has a little roundup of the early years of plastic watches, starting with 1971’s Tisson Astrolon. It’s amazing what a dose of “Delrin, Polyamide, Polyacette, Hostaform, Polystyrol, Lucite, Acrylic, Perspex and Bakelite” did to the stodgy world of watchmaking.
See also:
Mechanical “LED watch” from 1970
History of calculator watches
Steampunk watch
Belt-drive watch
Watch guts of great beauty
All-plastic watch movement from the 70s
Awesome, impractical, expensive watch