Pupillary changes during dark adaptation in human infants.

Pupillary diameter of 10 infants (age 10 weeks) and four adult subjects was measured during 30 min of dark adaptation following exposure to a full-field adapting light. Adult results confirm that, under these conditions, the course of pupillary recovery was reasonably well described by an exponential time course (t0 = 408 sec; SD = 42 sec), as is rhodopsin regeneration. Pupillary recovery of infants also could be described by an exponential course (average t0 = 399 sec; SD = 31 sec). These results, demonstrating similarities between adaptive functions of infants and adults, suggest that pupillographic techniques can be used to investigate dynamic processes accompanying dark adaptation in preverbal children.