30, 20, and 10 Years Ago in OPN

“Optical phenomena, optics devices and the history of optics and photonics can all be found in the fascinating world of philately … One of the most often pictured optical devices on stamps is the magnifying lens, universally used by collectors. The most unusual case is one of F.D. Roosevelt, who was a stamp collector, holding his lens. Upon close examination, he has six fingers. Other interesting design errors make looking for them a hobby in itself.”