Measurement of visual acuity has been the cornerstone of visual testing since Snellen began quantitating visual acuity using letter optotypes in the 1860s. Bjerrum in the 1880s brought sophistication and quantitation to the assessment of the visual field with tangent screen examination using differently sized and colored targets. Further advances in visual testing did not occur until the Goldmann perimeter and the Farnsworth Munsell 100 Hue test were introduced in the 1940s, permitting further refinement in the detection and quantitation of acquired visual loss. An explosion of interest in...