To establish whether or not glaucomatous damage is reversible, we obtained pattern-reversal electroretinograms (PERGs) and visual evoked potentials (VEPs) in 25 eyes of 25 patients suffering from bilateral primary open-angle glaucoma (POAG) before and after argon-laser trabeculoplasty. The laser treatment was carried out in only one eye chosen at random, and the fellow eye was used as a control. In the present study we intended to verify the possibility of using electrofunctional techniques to determine the two distinct and, probably, consecutive glaucomatous alterations occurring in ganglion cells: functional (reversible) and anatomical (irreversible). The results obtained indicate that glaucomatous damage is irreversible. We propose that such alterations differ very slightly and that the current electrofunctional techniques may not be sufficiently sophisticated to distinguish between them.