What could be wrong with my nearly 9 week old son's eyes?

Ever since my son we born his eyes have been getting gooey green gunk coming out of his eyes. My LMC told me to put some milk in them so I did for about two weeks and it cleared up for a few hours but then came back. We took him to the doctor last Friday and the doctor gave me some eye drops to put in his eyes which I did for a week. But that didnt do anything either. It doesnt hurt him or anything but it must get annoying. I've also tried using a cotton ball and some salt water and washed his ey every hour for a week and that hasnt worked either. Will this go away or should I get a second opinion frmo another doctor?