A visual field test is an eye examination that can detect dysfunction in central and peripheral vision which may be caused by various medical conditions such as glaucoma, stroke, pituitary disease, brain tumours or other neurological deficits.

Machine-based tests aid diagnostics by allowing a detailed printout of the patient's visual field.

[1][failed verification] It is the systematic measurement of differential light sensitivity in the visual field by the detection of the presence of test targets on a defined background.

[3] The minimum brightness required for the detection of a light stimulus is called the "threshold" sensitivity level of that location.

Perimetry testing is important in the screening, diagnosing, and monitoring of various eye, retinal, optic nerve and brain disorders.

This tests isolated L- and M-cone function and is applied in the setting of glaucoma.

[10] Following 30 minutes of dark-adaptation, it is possible to selectively test rod function using short-wavelength (blue) stimuli on a dark background.

[11] Today, it is also possible to perform this type of examination in eyes with unstable fixation using scotopic microperimetry.