Dawson W W, Michels M, Semple-Rowland S L
Doc Ophthalmol. 1984 May 30;57(3):181-6. doi: 10.1007/BF00143082.
Stimulus size, chromaticity, adaptation, luminance and local adaptation are more easily controlled when laser light rapidly scans the appropriate portion(s) of the visual field. Adaptation of a Ferree-Rand perimeter to the use of He-Ne laser light gives chromatic and achromatic thresholds of relatively low variance.