An animated description of the cause behind presbyopia (ageing eyes), read by James Ball, Ophthalmic Surgeon based in Leeds, UK

Text as follows: "Young people, who have perfect vision for distance, are able to use their soft crystaline lens to pull focus for near when they contract the ciliary body making the lens fatter. As we get older however, this crystaline lens stiffens up and we lose this ability to pull focus for near. So that objects such as books and magazines are blurred unless we put on reading spectacles."