Soviet army adopted a scout vehicle with thermal scope in mid 80s with 1PN59 “Benefit” scope. T80U had very good fire control system even without a thermals for 1985. Not even mentioning automatic tracking on some soviet-russian tanks. T-80U, T90 had Agava 2 installed in 1992, but Agava 2 was mentioned first in 1986, with the talks about Obj. 477, it was also proposed and tested for Obj 187 (better T-90A from 1989). Theres also predecessor to Agava 2, the og Agava, and while comparing to other thermals of the time it was horrible, it’s first prototypes appeared in 1982. There’s also “Benefit-2” sight from 1987,which was also tested on T-80U in same year . It’s not about them not having technology, its about them not being able to finish plans to make mass production for Agava 2 until 1990, when country is collapsing, many good prototypes are getting cancelled. In second half of 90s NOCTURNE sight was made, which was based ln Agava 2 and better than it. In 2010 there was Irbis sight made, a bit later thermal version of Agat sight. Even later there were Irbis K2 made, which is in use on T-90M ans T-14 (most likely), Irbis K2 is gen 3 thermal, unlike Irbis being gen 2 thermal.Theres also Boomerang series of thermals imagers for T-15, Kurganets, but its commander one, dont know what exactly gunner has, though i dont think I need to explain both platforms this is mounted on are extinct. The real provlem was commanders not having thermals for a long time.
Though, due to difficulties with mass producing and upgrading at the time (USSR collapse, economy crisis), even Uralvagonzavod decided to better take Belarus sights like ESSA, Sosna (which would be modified to Sosna-U) which had french Catherine FC thermal imagers, same found on Leclerk, if i am right.
Have made a lot of edits to add or correct info, if someone wants pictures of sights, I can provide on sight asked. Probably gonna stop for now, though I can say I have found plenty soviet-russian thermals and vehicles or prototypes with them mounted on.