Arc of vision

(Astron.) the arc which measures the least distance from the sun at which, when the sun is below the horizon, a star or planet emerging from his rays becomes visible.

See also: Vision

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Drivers have a certain arc of vision, while the rest of what they see comes from peripheral vision, Barnett said.