The Glasses is the 67th episode of the sitcom Seinfeld. It is the third episode of the fifth season, and first aired on September 30, 1993.
I could not find the full episode so here is a summary: George loses his glasses and cannot see until he gets a new pair. While not wearing his glasses, George thinks he sees Jerry's girlfriend making out with Jerry's cousin. George goes to Jerry with this information but isn't sure if he can trust George's eyesight. Jerry sets up a trap for his girlfriend to sees if she is cheating. When he thinks he has evidence he makes the accusation but is sorely mistaken. It turns out George actually saw a park ranger nuzzling her horse on the sidewalk.