Simply amazing. It's a wonderfully complete, well-researched treasure. I thoroughly enjoyed it, and I just wish I had a niece or nephew of the right age to receive a copy as a gift. I hold a PhD in optical physics, and I work in the field of optical design, and I found many stunning effects here that I can show to any colleagues who still retain a sense of wonder, but I'd love to give it to a curious 7-year old and initiate them into the fascinating world of visual perception. My edition seems to be slightly different to the current, but I don't imagine that Al Seckel has seen any need to make major changes. I have 256 pages, mostly given over to the full-page images, with a minimum of well-written text, just enough to whet the appetite for explanation, clear and simple enough for a child, accurate enough for a professional. Highly recommended.