The entrance pupil is the image of the lens’ aperture stop as seen from the front of the lens — through the glass elements in front of the iris — and that is normally where the iris is located.
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Vivamus quis neque vel quam fringilla feugiat. Suspendisse potenti. Proin eget ex nibh. Nullam convallis tristique pellentesque.
