It is important in following and documenting conditions to accurately measure them. The biomicroscope can be used in to do this in a couple of ways. One is to have a reticule with a millimeter scale in the eye piece. This is an accurate method but has a problem in that it must be calibrated for each magnification.
Another method is to use the width or height of the light beam or a known spot size. The beam is set to the width of the defect (scar, abrasion, neovascularization, etc.).
