Eye chart smaller towards the bottom of the chart. The person removes any glasses or contact lenses, and stands or sits a standardized distance from the chart (e.g., 20 feet for the Snellen chart). The person is then asked to identify the optotypes on the chart, starting with large rows and continuing to smaller rows until the optotypes cannot be reliably identified any more. The row in which the person can reliably identify symbols defines the visual acuity. One eye is tested at a time. Practically, this is accomplished by covering the other eye with a hand, piece of paper, or a
Four-letter word Four-letter word The phrase four-letter word refers to a set of English-language words written with four letters which are considered profane, including common popular or slang terms for excretory functions, sexual activity and genitalia, terms relating to Hell or damnation when used outside of religious contexts or slurs. The "four-letter" claim refers to the fact that a large number of (but not all) English "swear words" are incidentally four-character monosyllables. This description came into use during the first half of the twentieth century. Common four-letter words (in this sense) that are widely considered vulgar or offensive to a notable degree