Quiroga Mellado, Juan AntonioGómez Pedrero, José AntonioAlonso Fernández, JoséVargas Balbuena, Javier2023-06-202023-06-202010-09-200003-693510.1364/AO.49.005125https://hdl.handle.net/20.500.14352/43965© 2010 Optical Society of America. This work has been financially supported by the Spanish Ministry of Science and Technology through the project number DPI2009-09023. It has also benefited from the framework of the Spanish Optometry Network.This paper presents a deflectometric technique to measure the power of an ophthalmic lens as perceived by the user. It is based on a calibrated camera acting as a pinhole in order to measure ray deflection along the same path as the visual axis when the lens is held in front of the eye. We have analyzed numerically the accuracy of our technique, and it has been compared experimentally with a commercial "lens mapper" and with the real user power calculated from the measured topography of the lens surfaces to state the reliability and accuracy of the presented technique.engjournal articlehttp://dx.doi.org/10.1364/AO.49.005125http://www.opticsinfobase.orgopen access535Progressive-Addition LensOff-Axis MeasurementsPhase ObjectsCameraÓptica (Física)2209.19 Óptica Física