Objective determination of human visual acuity: pattern evoked potentials.

The natural visual acuities of 15 adult persons were predicted on the basis of changes in visual evoked potentials (VEP's) to flashed patterns of various sized dots. An objective method was used to quantify the VEP's, based on the minimum-sized stimulus that would elicit a pattern VEP- the VEP pattern threshold. This measure was highly correlated with recognition and resolution measures of perceptual visual acuity (r's as high as 0.89). The regression equation between the VEP measures and predicted perceptual measures of acuity enabled the objective estimation of perceptual acuity to within +/- 0.29 decimal units.