Inclusion Criteria:

Glaucoma Patients:

• IOP > 23 mmHg and < 28 mmHg (average of the two highest readings of the daily curve, from 8:00 a.m. to 6:00 p.m., six independent readings, one every two hours) without medical treatment;
• HFA with MD < - 2 dB; CPSD > +2 dB; fixation losses, false positive rate and false negative rate each less than 20%;
• best corrected visual acuity of 20/20 or better;
• one or more papillary signs on conventional color stereo-slides: the presence of a localized loss of neuroretinal rim (notch), thinning of the neuroretinal rim, generalized loss of optic rim tissue, optic disc excavation, vertical or horizontal cup/disc ratio greater than 0.5, cup-disc asymmetry between the two eyes greater than 0.2, peripapillary splinter hemorrhages;
• refractive error (when present) between -1.00 and +1.00 spherical equivalent;
• no previous history or presence of any disease involving cornea, lens, macula or retina;
• no previous history or presence of diabetes, optic neuritis, any disease involving the visual pathways;
• pupil diameter > 3 mm without mydriatic or miotic drugs.

Patients with non-arteritic ischemic optic neuropathy:

• IOP < 21 mmHg HFA with MD < - 2 dB; CPSD > +2 dB; fixation losses, false positive rate and false negative rate each less than 20%;
• refractive error (when present) between -1.00 and +1.00 spherical equivalent;
• no previous history or presence of any disease involving cornea, lens, macula or retina;
• no previous history or presence of diabetes of any further disease involving the visual pathways;
• pupil diameter > 3 mm without mydriatic or miotic drugs.

Exclusion Criteria:

All other condition that may influence Visual Evoked Potentials:

- previous history or presence of any disease involving cornea, lens, macula or retina or optic nerve (i.e inflammatory diseases)