A system for evaluating optical distortion in an aircraft transparency, such as a windshield, is disclosed. The system utilizes high resolution digital images (a reference image and a test image) of a test grid structure having a pattern of visible index locations. In one embodiment, the test image is taken through the transparency under test, and the reference image is taken without the transparency. The two images are processed and analyzed by a computing device to determine displacement of each index location, relative to the reference image. The displacement data is further processed to obtain vector divergence field data that represents a quantitative measurement of the optical distortion. The optical distortion measurement data is then rendered in a suitable format that allows the transparency to be rated against certain quality criteria.