Vision correction for computer users based on image pre-compensation with changing pupil size

Many computer users suffer varying degrees of visual impairment, which hinder their interaction with computers. In contrast with available methods of vision correction (spectacles, contact lenses, LASIK, etc.), this paper proposes a vision correction method for computer users based on image pre-compensation. The blurring caused by visual aberration is counteracted through the pre-compensation performed on images displayed on the computer screen. The pre-compensation model used is based on the visual aberration of the user's eye, which can be measured by a wavefront analyzer. However, the aberration measured is associated with one specific pupil size. If the pupil has a different size during viewing of the pre-compensated images, the pre-compensation model should also be modified to sustain appropriate performance. In order to solve this problem, an adjustment of the wavefront function used for pre-compensation is implemented to match the viewing pupil size. The efficiency of these adjustments is evaluated with an “artificial eye” (high resolution camera). Results indicate that the adjustment used is successful and significantly improves the images perceived and recorded by the artificial eye.

[1]  J. Schwiegerling Scaling Zernike expansion coefficients to different pupil sizes. , 2002, Journal of the Optical Society of America. A, Optics, image science, and vision.

[2]  Armando Barreto,et al.  HOWARD: High-Order Wavefront Aberration Regularized Deconvolution for Enhancing Graphic Displays for Visually Impaired Computer Users , 2006, ICCHP.

[3]  Guang-ming Dai,et al.  Scaling Zernike expansion coefficients to smaller pupil sizes: a simpler formula. , 2006, Journal of the Optical Society of America. A, Optics, image science, and vision.

[4]  Veikko Surakka,et al.  Pupil size variation as an indication of affective processing , 2003, Int. J. Hum. Comput. Stud..

[5]  C. Campbell Matrix method to find a new set of Zernike coefficients from an original set when the aperture radius is changed. , 2003, Journal of the Optical Society of America. A, Optics, image science, and vision.

[6]  Armando Barreto,et al.  Image pre-compensation to facilitate computer access for users with refractive errors , 2004, Assets '04.

[7]  Donald Decker,et al.  An evaluation of pupil size standards used by police officers for detecting drug impairment. , 2004, Optometry.

[8]  Armando Barreto,et al.  Evaluation of onscreen precompensation algorithms for computer users with visual aberrations , 2007, Assets '07.

[9]  Armando Barreto,et al.  Image pre-compensation to facilitate computer access for users with refractive errors , 2004, ACM SIGACCESS Access. Comput..

[10]  S. Steinhauer,et al.  Sympathetic and parasympathetic innervation of pupillary dilation during sustained processing. , 2004, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[11]  M. Alonso,et al.  Improving computer interaction for users with visual acuity deficiencies through inverse point spread function processing , 2005, Proceedings. IEEE SoutheastCon, 2005..

[12]  Larry N. Thibos,et al.  Formation and Sampling of the Retinal Image , 2000 .