Abstract: A lensmeter is disclosed for determining the refractive properties of a test lens, including an optical system to produce an ellipse of light at a detecting plane having information of such properties, a scanning linear photodiode array at the detecting plane for producing video output signals, a first integrator to integrate the video output signal from each photodiode, a compensator to compensate each video output signal for the light sensitivity of each photodiode, a second integrator to integrate the compensated video signals over the range of the distribution of light of an area of the ellipse being scanned, a circuit, connected to the second integrator, to detect the median point of the distribution, and a microprocessor to provide data identifying the median point in response to the detection.