(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.
Brief Summary. Papaver somniferum, opium poppy, is an annual herbaceous plant in the Papaveraceae (poppy family) that originated in southeastern Europe and western Asia, and are now widely cultivated in Europe, Asia, China, and North Africa for their seeds, which are used in baking, as a condiment, and for their edible oil.
Rules for the legal cultivation of opium poppies were set out in the United Nations' Single Convention on Narcotic Drugs in 1961. Countries that produce and export opium must keep a close watch on the poppy farms within their borders. In Turkey, for example, poppy farmers harvest both the opium and the seeds.