With his unique blend of informative text and illustration, master explainer David Macaulay explores one of the body's most amazing organs. How does the eye collect and focus light? How does the brain interrupt signals from our eyes so we recognize the things around us? It's a remarkable process that we never have to think about--we just have to keep our eyes open!

Follows the planning, construction, and ultimate testing in battle of a typical fortress with adjoining town built by the English in the thirteenth century as a part of their plan to conquer Wales.