Editing Visual field (section)

==Measuring the visual field==
{{main|Visual field test}}
The visual field is measured by [[perimetry]]. This may be kinetic, where spots of light are shown on the white interior of a half sphere and slowly moved inwards until the observer sees them, or static, where the light spots are flashed at varying intensities at fixed locations in the sphere until detected by the subject. Commonly used perimeters are the automated Humphrey Field Analyzer, Optopol Perimeters, Octopus, the Heidelberg Edge Perimeter, the Oculus or the Olleyes VisuALL.

Another method is to use a [[campimeter]], a small device with a flat screen designed to measure the central visual field.

Light spot patterns testing the central 24 degrees or 30 degrees of the visual field, are most commonly used. Most perimeters are also capable of testing up to 80 or 90 or even 120 degrees.

Another method is for the practitioner to hold up one, two, or five fingers in the four quadrants and center of a patient's visual field (with the other eye covered). This is also known as confrontational field testing.  If the patient is able to report the number of fingers properly as compared with the visual field of the practitioner, the normal result is recorded as "full to finger counting" (often abbreviated FTFC). The blind spot can also be assessed via holding a small object between the practitioner and the patient. By comparing when the object disappears for the practitioner, a subject's blind spot can be identified. There are many variants of this type of exam (e.g., wiggling fingers in the visual periphery on the cardinal axes).