The imaging of the optic disc is particularly clinically valuable for monitoring the progression of glaucoma. With slit lamp videography for our own glaucoma patients, observation periods of up to over 20 years are now available. Minor changes in the morphology of the optic disc can be detected much more accurately with the help of the so-called flicker test than by comparing images side by side. For example, an older examination is brought into alignment with a current videography on adjacent PowerPoint slides by shifting the image. Flickering between the images creates apparent movements at the locations with changes. Even experienced examiners will find that the flicker test has made the smallest marginal hemorrhages clearly visible to them.