(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.
Opium is a plant product derived from the sap inside of the opium poppy's seedpod. This poppy (papaver somniferum) grows in dry, warm climates, especially in the mountains stretching from Turkey through Central and South Asia all the way to Laos.