I've watched this again 35 years later
...and I'm still impressed in my sixties. It's true that the special effects could have been underwritten with (as I believe a TIME magazine review once put it) the change one might dig out from beneath the average sofa, but the underlying intelligence in this largely faithful adaptation of Le Guin's novel is profound. The last flick I caught that came anywhere near Lathe's level of philosophical inquiry was 2015's Ex Machina. That was a long time to wait.
Beyond its philosophical rewards, the film is almost musical in its presentation: there are just three major spoken parts (three minor, three almost negligible), and the principal dialogue amounts to a series of exchanges from these three voices: the patient, the therapist, the attorney.
I can't recommend this production highly enough, and I can't disparage the atrocious "remake" earlier this century with sufficient vehemence. If I ruled the world, every single "print" of that travesty would be destroyed.