Corneal endothelial cell CVs are indicative of the degree of cell size variability. A 20 year old should have a CV of 0.25, a 60 year old should have a CV of less than 0.35, and a CV of greater than 0.35 should be considered an abnormal value. Corneal endothelial cell CV refers to the coefficient of variation of the endothelial cell area size during corneal endothelial microscopy. The larger the CV value, the more uneven the cell size, which usually suggests that the corneal endothelium is unhealthy, whereas the smaller the CV value, the more uniform the endothelial cell area size is, and the corneal endothelium is relatively healthy. When conducting corneal endothelial cell examination, in addition to observing the CV value, it is also necessary to observe the density of corneal endothelial cells, as well as the proportion of hexagonal cells and other indicators, and comprehensively analyze the above indicators in order to come up with the most comprehensive and accurate judgment, and can not be based on a single indicator to make a judgment, otherwise it will lead to a one-sided result.