McIntyre D J
Ophthalmology. 1985 Mar;92(3):364-5.
In conjunction with ultraviolet filtration and to further minimize the risk of phototoxic retinal damage during anterior segment surgery, the operation microscope has been modified to eliminate on demand all light entering the eye by eclipsing the pupil when the red reflex is not required. Retinal light exposure may be reduced as much as 75%.