When i made the glasses for the model of Rei, i was getting worried because despite they being flat like real life glasses, the didn't looked good on all camera angles. Then i just saw that animators and artists just bend the glasses how they see fit depending on the angle of the camera/character head
just watched an episode of skeleton knight.. and an elf had glasses on.. aaahhh
btw, you took an great anime for your example pictures... shirobako is rly good :3