Very worried about my cats eye.

A few weeks ago, my cat Peanut had a cold. We gave him eye medication for 4 days. We were supposed to give it to him for a week, but my mother decided he was fine after 4 days. So we stopped.

About 2 days ago, he started tearing from one of his eyes. He kind of squints, and he sneezes a bit more then usual. 
I'm worried that something might be wrong with him. 

Here's a picture of what his eye looks like. 

http://i30.photobucket.com/albums/c340/flaminfrog280/peanut.jpg

I'm also worried about my other cat.
She's 6 1/2 months old, and I'm worried this might be contagious. 
We've started giving him his medicine again, but I think it would be better if we brought him to the vet.

What do you guys think?

Thanks in advance. 

If you have enough of the medicine, it might work to give it to him for the next 10 days or so. Stopping antibiotics too early is a perfect way to develop resistant bacteria. On the other hand, a vet visit might save him and you some significant trouble and pain.

Yeah I would be taking him back to the vet, and doing what the vet says, I know that sometimes they seem better but they still need to do the full course.

Hope Peanut is ok hes very pretty!

What medication(s) did the vet give you, and what did he/she, say Peanut had?