A noninvasive method has been developed that is capable of providing quantitative thickness profiles of the retina. The method was used to map the retinal thickness in five normal human volunteers and determine the reproducibility of the measurements. The reproducibility or equivalent sensitivity of the measurements to detect changes was found to be 5% or 19 microns on the same day and 8% or 31 microns on different days. By averaging the values obtained in five normal subjects, ranging in age from 21 to 43 years (mean, 34 years), a preliminary normal baseline was derived for the thickness profile at the fovea and the thickness cross-section from the optic disc to the fovea. The results of the study indicated that this noninvasive method promises to be of clinical use in diagnosing ocular diseases that produce changes in the thickness of the retinal as well as in monitoring the effectiveness of therapy.