(1834â1908), Dutch ophthalmologist. Snellen was director of an eye clinic at Utrecht. In 1862 he introduced a test for measuring the acuteness of vision which consisted of printed letters or words in type of various sizes.
The poppy of wartime remembrance is Papaver rhoeas, the red-flowered corn poppy. This poppy is a common weed in Europe and is found in many locations, including Flanders, which is the setting of the famous poem In Flanders Fields by the Canadian surgeon and soldier John McCrae.
This poppy is notable as an agricultural weed (hence the common names including corn and field) and after World War I as a symbol of dead soldiers. Before the advent of herbicides, P. rhoeas sometimes was so abundant in agricultural fields that it could be mistaken for a crop.However the only species of Papaveraceae grown as a field crop on a large scale is Papaver somniferum, the opium poppy.ts origin is not known for certain. As with many such plants, the area of origin is often ascribed by Americans to Europe, and by northern Europeans to southern Europe. Its native range includes West Asia, North Africa and Europe.