Glaucoma is a kind of progressive disease characterized by distinctive defects of optic disc cupping and visual field loss associated with or without intraocular pressure elevated.The cup/disc ratio is the standard way to describe the optic disc in the past 40 years.But the fact is that there were cases in which glaucomatous visual field loss was associated with a small cup,and cases in which visual field loss was not present even though the cup was large.The cup/disc ratio is less valid and reproducible than new methods.The Disc Damage Likelihood Scale(DDLS),which is based on the appearance of the neuroretinal rim of the optic disc,corrected for the disc diameter,may be a better system to evaluate the optic disc.