Arthur Marten Skeffington (1890 - 1976) was an American optometrist known to some as "the father of behavioral optometry".[1][2] Skeffington has been credited as co-founding the Optometric Extension Program with E.B. Alexander in 1928.[2] In the mid-1950s, Skeffington first diagrammed his "four circles" model of describing visual processing.[3]