Great to hear that his visit went well! I think you're referring to entropion, right? I don't have experience with it but a lot of members here have. Some, such as Chunk (@Chunksmama) required surgery, but a few also weren't severe enough to need one. I guess just watch out for it like what the vet said.
So cute how your vet wanted to write a note. Maybe you should've gotten one so you can shove it in that trainer's face. lol. (I'm really a nice person, honest! )