Vision testing system for testing the sight function of a patient

A vision testing system for testing the sight functions of a patient, the system comprising:

• polarization spectacles having first and second polarization lenses for placement in front of the first and second eyes of the patient, respectively;
• said first polarization lens defining a first polarization axis and said second polarization lens defining a second polarization axis perpendicularly to said first polarization axis;
• and,
• a vision testing apparatus including:
• a light source for radiating light defining a light axis;
• a first LCD-display mounted on said light axis downstream of said light source and including a plurality of first individually drivable liquid-crystal cells;
• a second LCD-display mounted on said light axis downstream of said first LCD-display and including a plurality of second individually drivable liquid-crystal cells;
• the cells of each of said displays being aligned with respect to each other and being adapted to each other with respect to their size;
• a color-neutral transparent first polarizer mounted on said light axis between said light source and said first LCD-display;
• a color-neutral transparent second polarizer mounted on said light axis between said first and second LCD-displays;
• said first polarizer defining a third polarization axis and said second polarizer defining a fourth polarization axis;
• said third and fourth polarization axes having different directions relative to each other;
• a first drive circuit for individually driving said cells of said first LCD-display;
• a second drive circuit for individually driving said cells of said second LCD-display;
• switching means connected to said first and second drive circuits for controlling both of said first and second drive circuits;
• and,
• key pad means for issuing commands to said switching means for driving said first and second drive circuits to, in turn, individually drive the cells of said LCD-displays.