Information on a tricky picture which is a skull from afar or lady brushing hair infront of a dresser if near?

I saw this drawing long time ago, it is a black and white print, I don't know it was done by whom. Anyone tell me where I can see or get this drawing??Information on a tricky picture which is a skull from afar or lady brushing hair infront of a dresser if near?
Found it!

All is Vanity by Charles Allan Gilbert is the original



http://en.wikipedia.org/wiki/Charles_All/a>



has been imitated and redone sinceInformation on a tricky picture which is a skull from afar or lady brushing hair infront of a dresser if near?
I think this is the work you're looking for;



Georges de La Tour. Repenting Magdalene, also called Magdalene in a Flickering Light. c. 1635-37. Oil on canvas. Los Angeles County Museum of Art



Here's a link so you can have a look.

http://www.abcgallery.com/L/latour/latou/a>
I know the one you are referring to. It's an optical illusion.