The Nobel prize winner at his best. This simple 150 pages makes quantum electrodynamics easy to understood. Why would a behavioral optometrist want to understand QED? Will it help decide the correct add for your next patient? No, but…. I found the book extremely insightful and full of examples which help understand much better the nature of light. So many of the problems we worked in geometric and physical optics turn out to be oversimplified special cases that don't really exist in the real world, or which only have a small wave of probability of existing. This book helped me gain insight into the power of lenses as we use them to transform the distribution of light over time for our patients. A number of the mind blowing demonstrations that Steve Cool, of Pacific College of Optometry, has done for years are fully explained in this little book. Does light travel only in the path of the angle of incidence equals the angle of reflection off a flat mirror? Can one photon interfere with itself through a double slit diffraction slit? Feynman explains these phenomena and many more.