Characterization of progressive addition lenses by measurement of the modulation transfer function using experimental ray tracing

Characterization of the optical properties of progressive addition lenses is not an easy task, mostly due to the strong change of the power and unwanted astigmatism, which depends on the viewing zone. Defining an appropriate figure of merit of a lens, independent of the subjectivity of test engineer has been a difficult task, but the modulation transfer function, perfectly fits this requirement as an widely accepted measurement of the performance of the lens which takes into account geometric and diffraction metrics regarding the contrast performance of the device under test against spatial frequency. Direct and indirect methods can be used to obtain the modulation transfer function of the optical system; in this work, it is calculated through the indirect method of calculating fast Fourier transform of the point spread function, which is obtained by calculating the wavefront error aberration function using experimental ray tracing. Real measurement data is compared to simulations using Zemax Opticstudio software.