Dark Addapted Pupillary Light Reflex Due to Short Time Laser Beam Exposure

The Pupillary Light Reflex (PLR) controls the amount of light entering the eye. This might protect the retina when exposed to laser radiation. Higher radiation power causes the pupil to close more and more rapidly. Using a 532 nm laser beam with radiation power between 100 pW and 100 μW causes the pupil diameter to decrease between 15.4 % to 42.4 %. The decrease starts after a latency period ranging from 160 ms to 300 ms. Contraction takes additional 360 ms to 1100 ms and is increasing with power. A duration of more than 600 ms passes before the pupil size reaches the minimum. The response varies with wavelength and it is shown, that the Spectral Luminous Efficiency Function can not be used to describe dependency.