Abstract

Over the course of infancy and early childhood, major changes in visual function occur. A clear understanding of these changes could lead to a more complete understanding of adult vision, because a good theory of vision must parsimoniously account for infant and adult vision and for the smooth transition between them that occurs during normal maturation. This paper summarizes what is known of rod and cone vision in human infants. We include morphology of the rods and cones, psychophysically measured absolute and increment thresholds, photosensitivities and spectral sensitivities of the receptor mechanisms, and the overall luminous efficiency function. The ability to discriminate between lights on the basis of differences in spectral composition emerges over the first three months of life. Four hypotheses are discussed concerning what critical immaturities are responsible for the poor color vision of very young infants: (1) a color vision deficiency of a recognized adult type, (2) extrafoveal detection of stimuli, (3) inadequate spatial resolution for chromatic stimuli, and (4) immaturity of chromatically opponent channels.

© 1986 Optical Society of America