Cat getting sick at the vet?

I just brought my cat home from the vet yesterday after he was neutered and declawed. Since having him home I have noticed that his third eye lid in his right eye is covering 1/3 to 1/2 of his eye. I am thinking I need to take him back to the vet tomorrow, but is this something that he could have caught from the vet? Any ideas what it could be?
Thanks!

It's actually quite common for kitties to come back from the vet sick. The stress of being at the vet lowers their immune system and they can more easily pick up stuff. Most likely, it's an upper respiratory infection. I'd definitely keep an eye on your kitty and watch for any signs of illness (change in behavior or appetite, sleeping more than normal, eye or nasal discharge anything but clear, and congestion & sneezing).

I dont know any of those things because I just got him and I dont know what would be him being sick and what would be just because he just had surgery and was moved to a new place. He has been an outdoor cat, so i don't know if this could be a parasite? Or I saw somewhere about Horner disease which sometimes happens with serious ear infections, so I dont know if it is that or not. I am leaving for the weekend tomorrow and don't know if I should take him into the vet tomorrow morning or not...

You just got him yesterday from a declaw and neuter... he is sick now after two traumatic surgeries... I really do hope you are not thinking about leaving him alone for the weekend already tomorrow?
Sorry to say, but IMHO that is really not a good time to leave him alone... not at all... He is in a new home, already a trauma on itself, plus the surgeries, plus the possible URI.
Is anybody taking care of the kitty? Anyway to delay your trip? Vibes for the kitty....
Also, please don't leave him outside now that he is declawed....

He's had some really big changes in his life and the stress is probably contributing to the illness. Give him time and lots of TLC and keep a close watch on him. If you think he needs to go back to the vet, then by all means, take him. Better to be safe than sorry in my book.

How's he doing today?

I hope you have an appointment at the vet just to confirm his health status.
for him!

If you just got him, it's possible he already was fighting an upper respiratory infection(URI) and the stress of the vet/surgery made the symptoms appear or get worse. Another possibility is he may have feline herpes, that can cause URI symptoms and stress often causes a flare-up.