Today, automated (computerized) field analyzers, such as the Humphrey or the Octopus perimeters are used to perform the field of vision test.
However, there is a different type of perimeter, the Goldmann perimeter, which is used in special circumstances such as in patients with limited cooperation or poor vision. Depending upon the size of the test stimulus, a Goldmann perimeter maps out the outer margins of the visual field. Current visual field criteria that define legal blindness in the US are based on Goldmann perimeter.