Norman Walsh recently posted a link to Akiyoshi's illusion pages. I've got to say these are really fantastic. They are excellent illustrations of the physiological factors that make our vision work the way it does.

Vision and Art cover I recently read Margaret Livingstone's Vision and Art: The Biology of Seeing, and although it's not the sort of book I would have bought for myself (my mother gave it to me as a birthday present), it's excellent. It made me a lot more aware of how human vision works and evolved — things I always had a general idea of, but not much in the way of specifics. This book really made a lot of those ideas a lot more concrete for me, and illustrated them with artwork and optical illusions that demonstrate them.

A number of the book's illustrations are remarkably similar to many of Akiyoshi's illusions.

On a related note, via Dave Shea, for anyone interested in colour and luminance contrasts, and colour blindness (topics covered in Vision and Art), I highly recommend Pixy's Colour Scheme Picker. It's a client-side web application that lets you explore colour combinations, and how they might appear to people with different forms of colour-blindness — well worth bookmarking.