Topography on the ocular fundus has been achieved with the technique projecting grating images onto the fundus and detecting deformations of the grating images. In this technique, a well known subtraction method has been adaptedby making the grating displace rapidly and recording two grating images before and after the displacement. Consequently, it is found that thesubtraction method is very available to the excavation depth measurements, and the excavation of most normal eyes can be automatically analyz-ed with simple image processing. For measurements of same normal eyes, the excavation at themaximum depth is obtained with high reproducibility. For the contour-mapping displays of the ocular fundus, it has been found that available differences between normal and glaucomatous eyesare obtained.