Abstract: Glaucoma is characterized mainly by optic nerve injury, and the assessment of optic nerve injury contributes to research of its etiology and pathogenesis. The current assessment methodology mainly includes determination of retinal ganglion cell (RGC) number, counting of lining retinal thickness and optic nerve axons. Those methods have their own advantages and disadvantages. Apoptosis of RGC directly reflects the degree of optic nerve injury. RGC counting operates easily with retina\|stretched preparation, but the layers of cells are apt to overlap reciprocally. The retrograde fluorogold labeling of retinal ganglion cells possibly leaks out into neighboring microglia, and accordingly results in the inaccuracy of the count. The retinal thickness measurement is not directly reflected injury severity and the optic nerve axons counting is not operationally easy in some ways. The stereological method can be used for RGC counting, however relevant formulas and methods need to be mastered, and it is rarely reported in this field.  (Int Rev Ophthalmol, 2015, 39： 99-102)