Today's Word of the Day means...
"When you have seen one of their Pictures, you have seen all." [Blake, c.1811]Sense of "escort" (e.g. to see someone home) first recorded 1607 in Shakespeare. Meaning "to receive as a visitor" is attested from c.1500. Gambling sense of "equal a bet" is from 1599. See you as a casual farewell first attested 1891. Seeing Eye dog first attested 1929, Amer.Eng., trademarked by Seeing Eye Inc. of New Jersey.
[first noun sense perhaps an abbreviation of commendation]
in astronomy, sharpness of a telescopic image. Seeing is dependent upon the degree of turbulence in the Earth's atmosphere for a given telescope. Scintillation, the "twinkling" of stars to the unaided eye, is a commonly known result of turbulence in the higher reaches of the atmosphere. Poor seeing in telescopes is more a result of turbulence in the lower atmosphere. This turbulence sets a limit on the features that a telescope can resolve.