Method and apparatus for vision acuity testing

1. A method of operating a data processing system for displaying an eye test pattern on a computer display to a patient during an eye examination, said method comprising:

causing said data processing system to display said eye test pattern in a chart region of a computer display controlled by said data processing system and characterized by a luminance in regions not displaying said eye test pattern;

measuring an intensity of light leaving said computer display in a sensor region outside said chart region using a display luminance sensor; and

adjusting said luminance of said computer display to provide a light level within a predetermined range of light levels based on said measured intensity of light.

2. The method of claim 1 wherein adjusting said luminance comprises receiving said measured intensity by said data processing system and automatically adjusting said computer display in response to said measured intensity.

3. The method of claim 1 wherein said intensity of light is measured by a sensor that views a portion of said computer display and wherein said sensor communicates directly with a user of said data processing system with instructions on changing said luminance of said computer display.

4. The method of claim 1 further comprising providing an ambient light sensor proximal to said patient's eyes that measures an ambient light intensity in a room containing said patient and causing said data processing system to alter said ambient light intensity in said room such that said ambient light intensity in said room is within predetermined limits.

5. The method of claim 4 wherein said ambient light sensor is positioned such that light from said computer display is not directly received by said ambient light sensor.

6. The method of claim 1 further comprising measuring said luminance of said display in said chart region, and measuring said luminance in said sensor region, said data processing system calibrating said measured luminance in said sensor region to said measured luminance in said chart region.

7. The method of claim 6 wherein said display luminance sensor is used to measure said luminance in both said chart region and said sensor region.

8. The method of claim 1 further comprising:

providing a glare light source proximately located to said chart region, said glare light source being characterized by a glare luminescence;

measuring said glare luminescence with said display luminance sensor; and

causing said data processing system to adjust said glare light source such that said measured glare luminescence is within a predetermined range.

9. A vision testing system comprising:

a data processing system that includes a computer display, characterized by a display luminance, on which said data processing system displays an eye test pattern in a chart region of said computer display;

a luminance sensor that measures a light intensity in a sensor region of said computer display, said sensor region being outside of said chart region; and

a display intensity adjustment system that receives an output from said luminance sensor and causes said computer display to change said display luminance such that said output from said luminance sensor output is within predetermined limits.

10. The vision testing of claim 9 wherein said display intensity adjustment system is separate from said data processing system.

11. The vision testing of claim 9 wherein said display intensity adjustment system comprising a program running on said data processing system which automatically adjusts said display luminance in response to said measured light intensity in said sensor region.

12. The vision testing of claim 9 wherein said display intensity adjustment system comprises an interface that instructs a user of said system to manually change said display luminance.

13. The vision testing of claim 9 wherein said luminance sensor reversibly attaches to said computer display.

14. The vision testing of claim 9 wherein said luminance sensor is powered by light received from said computer display.

15. The vision testing of claim 9 further comprising an ambient light sensor positioned proximate to a patient's head that measures ambient light at a location of a patient's eyes and to communicate said measured ambient light to said data processing system.

16. The vision testing of claim 15 wherein said data processing system causes said ambient light to be changed such that said measured ambient light is within predetermined limits.

17. The vision testing of claim 9 further comprising a glare source comprising a light source in close proximity to said chart region, said glare source emitting light characterized by a glare luminescence, wherein said illumination sensor measures said glare luminescence and said data processing system adjusts said glare luminescence such that said glare luminescence is within a predetermined range.