On the focal distance of the eye during sighting in pistol shooting.

We measured the focal distance and pupil diameter on the eyes of 11 marksmen sighting a pistol target at 23 m distance. Both upon the focal distance and pupil diameter of the subjects, we estimated the point at which they were looking during sighting. Calculation based on depth of field which can be divided from the pupil diameter of 4.5 mm suggested that the subjects were looking at the foresight of the pistol approximately 80 cm in front of the eye during sighting.