Cyclops

The mythological Greek race of one-eyed giants. In recent years, in major tournaments, a new device has been installed that, by means of an electric eye, emits a sharp beep when a serve hits the surface of the court just past the receiver’s box, thus relieving the linesman or the umpire of having to make a difficult call of whether or not the service was a fault. The irrepressible Bud Collins dubbed the electric eye “Cyclops.”