Abstract: Methods and apparatus are provided for measuring contrast sensitivity. In one method, a person is presented with a test pattern having several test areas. In a first test cycle, one of the test areas contrasts with (for example, is darker than) the other test areas. The person being tested indicates which test area the person perceives as contrasting with (darker than) the other test areas. This is repeated a number of times for the other test areas, with the level of contrast staying the same but with a different test area becoming the contrasting (darker) test area. In subsequent cycles, these steps are repeated, with decreasing levels of contrast. The contrasting test area may, for example, appear as a solid, as a pattern such as two contrasting vertical bars, or as an animation such as a sinusoidal frequency grating.

Abstract: Methods and apparatus are provided for measuring contrast sensitivity. In one method, a person is presented with a test pattern having several test areas. In a first test cycle, one of the test areas contrasts with (for example, is darker than) the other test areas. The person being tested indicates which test area the person perceives as contrasting with (darker than) the other test areas. This is repeated a number of times for the other test areas, with the level of contrast staying the same but with a different test area becoming the contrasting (darker) test area. In subsequent cycles, these steps are repeated, with decreasing levels of contrast. The contrasting test area may, for example, appear as a solid, as a pattern such as two contrasting vertical bars, or as an animation such as a sinusoidal frequency grating.

Abstract: A method is provided of comparing eye fundus slides for analysis. This method includes using an archival slide for a reference, preparing a current eye fundus slide and comparison with the reference and using a two-projector system for superimposing the image of the current eye fundus slide on the image of the reference.