Tests of visual function provide the clinician with essential information regarding the performance of a patient's visual system. At the present time, primary open-angle glaucoma is diagnosed by means of specific patterns of peripheral visual field loss and characteristic appearances of the optic nerve head. The “gold” or reference standard used to investigate peripheral visual function is evaluation of the visual field or perimetry. Visual field testing has been used for more than 150 years<sup>31 Duke-Elder S.   Text Book of Ophthalmology. St. Louis: Mosby (1938). 

Cliccare qui per andare alla sezione Riferimenti</sup> and represents the most common method of assessment of peripheral visual function. The ability of perimetry and visual field testing to provide useful clinical information has been responsible for its long-term use as a diagnostic procedure. Although a variety of stimuli may be used for perimetric investigations, this article concentrates upon describing achromatic (white-on-white) perimetry with particular reference to the Humphrey Field Analyzer. Two recently developed visual field testing procedures that have demonstrated clinical utility are also discussed: short-wave automated perimetry (SWAP) and frequency doubling technology (FDT) perimetry.

It is important for the reader to recognize that glaucoma may also produce adverse effects upon a variety of other nonperimetric visual functions. Glaucoma has been reported to degrade central color vision,<sup>92 Sample P.A., Weinreb R.N., Boynton R.M. Acquired dyschromatopsia in glaucoma Surv Ophthalmol 1986 ;  31 : 54

Cliccare qui per andare alla sezione Riferimenti</sup> both spatial<sup>8 Arden G.B., Jacobson J.J. A simple grating test for contrast sensitivity: Preliminary results indicate value in screening for glaucoma Invest Ophthalmol Vis Sci 1978 ;  17 : 23

Cliccare qui per andare alla sezione Riferimenti</sup> and temporal<sup>104 Tyler C.W. Specific deficits of flicker sensitivity in glaucoma and ocular hypertension Invest Ophthalmol Vis Sci 1981 ;  20 : 204

Cliccare qui per andare alla sezione Riferimenti</sup> contrast sensitivities, vernier acuity,<sup>79 Piltz J., Swindale N., Drance S. Vernier thresholds and alignment bias in control, suspect and glaucomatous eyes J Glaucoma 1993 ;  2 : 87

Cliccare qui per andare alla sezione Riferimenti</sup> and visual acuity by end-stage disease, although these functions appear to lack the discriminatory power of standard automated perimetry.