what is wrong with my cat?

i am worried about my 1 year old cat.  he vomited 3 or 4 times yesterday, didnt eat anything and layed in his bed all day. i talked to a vet about it and she said "wait and see if he is like this tomorrow. if so, bring him". today he didnt vomit but is still in his bed. an hour ago he jumped on my lap and i thought he was getting better. but now i noticed that one of his pupil is smaller than the other one. what do you think it may be?

Welcome to TCS.  I'm sorry it's under these circumstances but hope your kitty feels better soon.  This is a wonderful site - a good resource for information on all things cats and everyone is very friendly and caring.  

I would recommend you take your boy to the vet on Monday, just to be on the safe side.  Is he eating at all?  It's important to keep him eating so keep an eye on this.  The following will give you some info on this:
[article="32998"]Why Has My Cat Stopped Eating And Is It Dangerous  [/article][article="33011"]How To Get Your Cat To Start Eating Again  [/article]
The fact that he's no longer vomiting is encouraging but the unevenly dilated pupils can indicate an underlying health issue that should be checked out.   Sometimes this resolves on its own, just as the vomiting does but it is always best to be sure there is nothing serious going on.  In the meantime, keep a very close eye on him.  

We would love to see some photos of your boy.  And, tell us his name!