Determination of the proper checkerboard target for V.E.R. refraction

The VER will be in widespread use in optometric clinics within the near future. The VER, in the experimental laboratory, is showing itself to be a valuable tool in precise objective measurements in the visual analysis of an individual. The VER will not only be able to do refractions, but will be able to take phorias, ductions, measure fixation disparity, color vision defects, visual acuity, and check on the cause of amblyopia. In doing refraction, the sinusoidally presented checkboard has proven to be the best visual stimulus. This paper deals with trying to determin the optimum checkboard parameters in doing clinical refraction. These parameters include pattern rate and relative contrast.