This eye exam determines the visual field - it refers to the total area in which objects can be seen in the side (peripheral) vision while you focus your eyes on a central point. Humans have about 180-degree forward-facing horizontal field of view and 60 degrees up and down. Perimetry is important and necessary test for many diseases of the optic nerve and brain, glaucoma, stroke, tumors, etc. The most accurate method of examining visual field is computer perimetry. It is one of the most important examinations needed to detect and monitor patients suffering from glaucoma. In our clinic for perimetry is used Octopus.