How can I help this kitty?!

Meet my little buddy, Duke.

See what's going on there on his nose. Any ideas?

He is a mostly outdoor cat, who comes in usually just to eat.

The nose thing has been getting progressively worse over the last couple months, and today we noticed his lower left eyelid, not next to his nose, but under the other side of his left eye, is swollen and red-ish. Not sure if it's related to what is on his nose.

Was thinking of spraying (he'd probably rather be sprayed in the face, than held down) some colloidal silver on both. I'm going to surf around online for some answers, but I thought I would pick your brains first.

Thanks for your input and/or sharing this with anyone who might know something that could help.