Slooter J
Doc Ophthalmol. 1981 Mar 20;50(2):389-99. doi: 10.1007/BF00158023.
The response of the pupil was measured to a foveally fixated small field in which a checkerboard was alternated with a blank field of equal luminance. Visual acuity was assessed with pupil responses in 70 subjects who visited our clinic. A high correlation was found between the visual acuity as measured with pupil responses and the subjective acuity, using the same checkerboard stimuli. We also compared the visual acuity as measure with with pupil responses with the Snellen acuity. The method of obtaining pupil visual acuity seems to compare favourable with other objective methods of measuring visual acuity.