INTRODUCTION
Visual field testing is important for the diagnosis of glaucoma and even more important for follow up and management of glaucoma. Advanced glaucomatous loss is defined according to Hodapp, Parrish and Anderson's classification as mean deviation less than -12 dB or more than 37 points depressed below the 5% probability level or more than 20 points below the p < 1% level or absolute deficit (0 dB) in the 5 central degrees or sensitivity < 15 dB in the 5 central degrees in both hemifields. There is a limit to the visibility of the standard size III white perimetric stimulus in the patients with significantly impaired visual sensitivity. In order to increase the dynamic range into the low vision region and to make the stimulus more visible to these patients the Goldmann stimulus size V is typically used, instead of the standard size III. It is 16 times larger in area and is therefore more detectable.