jump(redirected from jumped down throat)
Also found in: Dictionary, Thesaurus, Legal, Encyclopedia.
Related to jumped down throat: jump down someone's throat
The displacement of the image of an object occurring when viewing across the borderline between two portions of different power in a bifocal or trifocal lens. The jump is eliminated by placing the optical centres on the dividing line; the lens is then called a no jump bifocal (e.g. a monocentric bifocal with a straight dividing line) (Fig. J1). Syn. image jump; prismatic jump. See monocentric.