Apologies for the lack of head****ing last Sunday (we had an inspection of all the house electrics the next day, plenty plenty tidying needed!) To make up for it, here are links to a bumper crop of stereograms to give you eyestrain in time for Monday morning.
Taken from Eyetricks.com, who have over 100 more examples for you to go goggle eyed over.
Being able to see into stereograms is a bit of an acquired skill but it's easy once you know how. I find the best way is to pick 2 bits of the picture that look the same and go cross-eyed so they merge together. If you're not sure how best to view the pictures, here's some handy hints from Eyetricks.