So the Snow Elves became the Falmer when they were forced underground by men and the Dwarves enslaved them and blinded them. So... What if someone, say the Mage's College, imprisoned a couple of hundred and released them on the surface. What would they do and would they ever again become their former selves? Obviously not overnight, but after a couple of hundred years. Would they stay on the surface or try and go back underground?

Released them on the surface? Either they'd murder a few villages, or they'd all fall off a cliff or something due to being unable to sense their surroundings properly.

Anyway, I doubt that there's any "getting better" for them, save for divine aid either from their old gods or from some spiritual movement within their people (if such a thing is possible). As far as the corruption of a race goes, things basically always get worse and never better in TES. Unless you're the Dunmer (and possibly certain groups of Orcs) who convince themselves that the change was for the best.

This leads along a different line of thinking: Falmer can never become Snow Elves because Snow Elves believe in something akin to Altmer ideals of ascendence. The corrupt Falmer are probably too far gone for such things. However, they could become something different, and possibly better. From a Thalmor perspective, Falmer are probably better than Men. And non-mer folk have still manage to achieve impressive things. It's a matter of perspective really.

I think they would never become the same again. They may recover a little bit but not change back to original Snow Elves.

Side Note: Topic says "Could the Falmer because Snow Elves again?"

I doubt they'll return to normal. Too much brain damage and genetic breakdown. Most they might be over time is some genius race that can focus on one or two subjects per individual or as a race while still having alot of mental instability. Sort of like a psychotic version of the Morrowind mages but with perhaps a demented sense of humour