Optic nerve injury is a common nervous system disease. Its basic pathological features are axonal degeneration and apoptosis of retinal ganglion cells(RGCs), which causes numbers of symptoms including visual dysfunction. Axonal degeneration, including axonal selective degradation, Wallerian degeneration induced by axonal transection, and apoptosis-induced axonal degeneration(axonal apoptosis), is an important part of neurodevelopment, axonal remodeling, and injury response process. Axonal degeneration is one of the initial steps in many traumatic neurological disorders, and damaged axons are generally unable to regenerate, which leads to neuronal cell apoptosis. Neuronal apoptosis causing the degeneration of both cell bodies and axons commonly occurs during the development of brain, as a result of various neuronal damages. Studies in recent years have confirmed that calcium is the main regulator of axonal degeneration. When an optic nerve crush(ONC)occurs, the degree of acute axonal degeneration(AAD)can be reduced by using calcium channel inhibitors to prevent the influx of calcium ions into axons, which will also improve the survival rate of RGCs and accelerate the regeneration of axons.