Difference In Pupil Size Research Articles

Normal Pupil Size and Anisocoria in Newborn Infants

The incidence of anisocoria in the newborn period is not well described. Additionally, the normal range of infant pupil size is not well defined. Eight-eight healthy newborns were evaluated. Pupil size and color were obtained from photographs. The mean (+/- SD) pupil size was 3.8 +/- 0.8 mm. There was no statistical difference between right and left eyes. A statistically significant difference in pupil size was found between blue and brown eyes. The incidence of anisocoria was found to be 21%. No difference was greater than 1.0 mm. The incidence of anisocoria was no different on the basis of eye color.

Pupil size, information overload, and performance differences.

ABSTRACTAs a test of the hypothesis that pupil dilation during performance is partially due to a task related anxiety component, pupillary patterns were measured while subjects (Ss) processed digit strings of various lengths for immediate recall. Information overload resulted in a leveling of the dilation pattern which suggested a momentary suspension of processing effort. In addition, significant correlations were observed between individual differences in pupil size and recall performance.

A Correlation between Pupillary Area and Retinal Sensibility

An analysis of the experimental data from fifteen subjects indicates that the variation in retinal sensibility between the subjects is of the same order as the variation in the areas of the natural pupils. It is also evident that pupillary area and retinal sensibility are opposing factors with respect to their possible influence upon the level of illumination selected by an introspective appraisal of seeing. In general, the subjects with the larger pupils usually have the lower retinal sensibility, and vice versa. Differences in pupil size and in retinal sensibility account only in part for the wide differences in levels of illumination selected as desirable by various subjects for a given critical visual test, such as reading. Apparently these differences are not chiefly due to physiological factors associated with the visual sense. From the Lighting Research Laboratory of the General Electric Company. An analysis of the experimental data from fifteen subjects indicates that the variation in retinal sensibility between the subjects is of the same order as the variation in the areas of the natural pupils. It is also evident that pupillary area and retinal sensibility are opposing factors with respect to their possible influence upon the level of illumination selected by an introspective appraisal of seeing. In general, the subjects with the larger pupils usually have the lower retinal sensibility, and vice versa. Differences in pupil size and in retinal sensibility account only in part for the wide differences in levels of illumination selected as desirable by various subjects for a given critical visual test, such as reading. Apparently these differences are not chiefly due to physiological factors associated with the visual sense. From the Lighting Research Laboratory of the General Electric Company.