old or young?

[jinty133]

Can anyone tell me where the name of the web site where puzzles are - i remember seeing one - a picture of an old lady, but you could also see a young lady. It was one of those pictures where your mind had to be re-adjusted to see either of the two ladies.

[squarebear]

Here you go:

http://mathworld.wolfram.com/YoungGirl-OldWoma nIllusion.html