Skin off your nose/mud in your eye

I have heard the following two phrases used, but have no clue as to what they mean:
Skin off your nose
Mud in your eye.

Can someone help decode them?

Thanks,
nrk.

Look here:

www.phrases.org.uk bulletin_board 6 messages 411.html

www.phrases.org.uk bulletin_board 6 messages 1131.html