title: Interferometric Local Measurements of High-Order Aberrations in Progressive Addition Lenses.
abstract: OBJECTIVE
  The main goal of this work is to show the principles, design, and performance of a modified point diffraction interferometer (PDI) for evaluating the local higher-order aberrations of progressive addition lenses (PALs). Because aberrations have different impacts in visual perception, we propose a device to provide a customized solution with the best permissible amounts and combinations of aberrations for improving a subject's vision.
  
  
  METHODS
  A PDI has been adapted to measure local high-order aberrations in PALs.
  
  
  RESULTS
  High-order aberrations in three different PALs within four relevant circular regions of interest (ROIs) with a radius ranging from 0.4 to 2.4 mm were measured with an accuracy of λ/10 within the ROI using the tailored PDI. The interferometer also allows for easily choosing the position and number of the ROIs.
  
  
  CONCLUSIONS
  The interferometric device is compact, robust, and accurate. The operational principle is very simple, and it provides the local high-order aberrations directly without adding additional parts to the interferometer. As expected, the amount of high-order aberrations depends on the chosen ROI of the PAL; the corridor is the more critical region. We found, in accordance with the literature, that, in the corridor, second- and third-order aberrations are dominant and spherical aberration is negligible.
authors.affiliation: *PhD INDO Optical SL, Sant Cugat del Vallés, Barcelona, Spain (SC); University of Arizona, Tucson, Arizona (JS); and Universidad de Santiago de Compostela, Santiago de Compostela, Spain (EA).
authors.forename: Sara
authors.initials: S
authors.lastname: Chamadoira
authors.forename: Jose
authors.initials: J
authors.lastname: Sasian
authors.forename: Eva
authors.initials: E
authors.lastname: Acosta
mesh_terms: D005139:Eyeglasses; D007368:Interferometry / Q000295:instrumentation*; D055095:Optics and Photonics; D014796:Visual Perception