A vision testing system includes polarization spectacles having different polarization axes with or without .lambda./4 filters for the two polarization lenses forward of the eye of the patient to be tested. This system also includes a vision testing apparatus for generating light having a specific polarization...http://www.google.com.au/patents/US5331358?utm_source=gb-gplus-sharePatent US5331358 - Vision testing system for testing the sight function of a patient
