The term pupil is used to describe an area that exists inside a three dimensional space, the eye, and while that space may not have anything that reflects light, it_does_contain something. The surface of the eye, known as the lens, and the liquid or ‘jelly’ that is contained inside the eye. So that area that is light reflective material would include the whites and the iris, but the inside of the eye is not just empty space. If it was, your eye would collapse like an uninflated beach ball, and you wouldn’t see very much at all. Arguably the term pupil is used to refer to the non-reflective area of the eye bordered by the iris and containing the lens.
Well yes, but also no.
The term pupil is used to describe an area that exists inside a three dimensional space, the eye, and while that space may not have anything that reflects light, it_does_contain something. The surface of the eye, known as the lens, and the liquid or ‘jelly’ that is contained inside the eye. So that area that is light reflective material would include the whites and the iris, but the inside of the eye is not just empty space. If it was, your eye would collapse like an uninflated beach ball, and you wouldn’t see very much at all. Arguably the term pupil is used to refer to the non-reflective area of the eye bordered by the iris and containing the lens.