Which of the following statements about processing of information in the eye are correct?
a) In order to focus on distant objects, the ciliary muscle contracts, this tightens the suspensory ligaments and the lens flattens.
b) The refractive power of a lens system is a measure of how much that lens system will converge or diverge light and it is expressed in dioptres.
c) Shining a torch in one eye will result in a reduction in the pupil size of that eye and also of the other eye; this is known as the "direct light reflex".
d) The depth of field is the distance over which an object can be moved towards or away from the viewer and still remain in focus.
e) The focal length of the eye is the distance between the lens and the point in the eye where the light is focused and is around 17mm in humans.