Infrared transillumination stereophotography of normal iris.

We studied the structure of the normal iris as seen in infrared transillumination photographs of variously pigmented eyes in subjects of different age and sex. To transilluminate the iris infrared light was passes via a fiber-glass optic through the lateral wall of the globe and photographs were taken with a Zeiss stereo slit-lamp camera. The photographs showed that the structural pattern of the iris was similar in both blue and brown eyes of either sex. The iris was rather dense in children, well developed in adults and somewhat atrophic in the elderly. On the posterior surface of the iris the radial contraction folds and the structural folds of Schwalbe and circular contraction folds were seen; they were delicate in children and more pronounced in adults and the elderly. The pupillary part of the iris ballooned forward in young people whereas in the elderly the whole iris had this configuration.