30.3 MB (2.5 MB compressed)
3979 x 2663 pixels
33.8 x 22.6 cm ⏐ 13.3 x 8.9 in (300dpi)
TREVOR CLIFFORD PHOTOGRAPHY / SCIENCE PHOTO LIBRARY TREVOR CLIFFORD PHOTOGRAPHY / SCIENCE PHOTO LIBRARY
Large pupils in low light. Close-up of a woman's face, showing how a person's pupils become enlarged when exposed to dim lighting conditions. This is caused by a relaxation of the iris sphincter muscle in response to the low light, a response known as the pupillary light reflex.
Model release available. Property release not required.