We had a similar thing happen to our chick, except we thought she was blind, and her eye lids became stuck open with the dried discharge.
So because of that, I just cleaned our chick's eyes/lids every night with warm water, cotton balls, q-tips, and then rinsed her eyes with saline. And then we got her into a vet because we thought she was completely blind, or... one of the hundred things chicks can get that kills them. And we (I) got sooooo attached to her!
The vet gave us Ofloxacin Ophthalmic Solution, (which I gave to her 6x a day for 5 days) and said that it was an eye infection. Right now (a week later) she's doing much better, and there is much less discharge- so it seems to have helped.
Long story short, (If it's not too late to say that) my advice is if it seem to get really bad, take her to a vet. But in the mean time, clean the discharge off, and make sure she's eating and drinking. If she's weak, I strongly suggest giving her Nutri-Drench. It saved our chick's life when she wasn't eating because she couldn't see the feeder that well.