kitty cold, and eye infection

I recently got a second cat from the local shelter, and he had upper respiratory. It cleared up a few weeks ago, but now my other cat has come down with it. She also has an eye infection that I am really worried about. My question is do I need to take my cat to the vet, or will this clear up on it's own.

I would take it to the vet.

The same thing happened with my cats. My resident cat who got sick also had a lot of eye discharge (a symptom the shelter cat didn't have) and looked like he was constantly crying. I made sure to keep giving them both antibiotics and wiping my cat's eyes constantly. His eyes have cleared up, but he's still sneezing and coughing so hopefully that will clear up soon.