Standard in perimetry is
Goldmann's perimeter: It consists of a hemispherical dome. Its main advantage over the tangent screen is that the test conditions and the intensity of the target are always the same. It permits greater reproducibility, Goldmann perimeter stimuli I through V. Unless otherwise instructed, the equivalent to Goldmann size III (4 mm2) white target. Reference : AK KHURANA COMPREHENSIVE OPHTHALMOLOGY, Edition4, Page-483,484
Goldman type I
Goldman type II
Goldman type III
Goldman type IV
Anatomy, Development and clinical examination