Charly (marketed and stylized as CHAЯLY) is a 1968 American drama film directed and produced by Ralph Nelson and written by Stirling Silliphant. It is based on Flowers for Algernon, a science-fiction short story (1958) and subsequent novel (1966) by Daniel Keyes.
The film stars Cliff Robertson as Charly Gordon, an intellectually disabled adult who is selected by two doctors to undergo a surgical procedure that triples his IQ as it had done for a laboratory mouse who underwent the same procedure. The film also stars Claire Bloom, Lilia Skala, Leon Janney, Dick Van Patten and Barney Martin.
I saw this on TV a long while back. It’s a good movie and the book was also good.