Is this dark drainage coming from my kittens eye okay?

He is draining dark colored liquid from his eyes. It comes out clear and drys dark like an "eyebooger" he gets those too wich are also dark colored. He sneezes here and there when he digs his nose in litter or smells something he doesn't like. So he sneezes from normal things. I'm just wondering if this drainage from his eyes is okay or not. He plays, eats, sleeps, and pottys great. Its just his eyes Im wondering about. He started draining a few days after we got him. He was 6 1/2 weeks at the time. He's about 11 weeks now. Could someone help me out?