How to get rid of darkish spots on nose from wearing glasses?

I wear contacts and glasses. over the past 3 months I have began to get darkish...almost tan spots where my glasses nose pieces are. I want to know how to get rid of them without make-up.(I believe they are from when I sweat the nose pieces rub against my nose.How to get rid of darkish spots on nose from wearing glasses?
I wear both too! I found that wearing plastic frames that didn't have the nose pieces didn't do that to me as much. My eye doctor said it was a form of bruising so she recommended that I wear plastic frames. there are some pretty cute ones out there.