Classical theories suggest that the surface area of the crystalline lens changes during accommodation while the lens volume remains constant. Our recent work challenged this view by showing that the lens volume decreases as the lens flattens during un-accommodation. In this paper we investigate: a) the magnitude of changes in the surface of the in vitro isolated cow lens during simulated accommodation, as well as that of human lens models, determined from lateral photographs and the application of the first theorem of Pappus; and b) the velocity of the equatorial diameter recovery of pre-stretched cow and rabbit lenses using a custom-built software-controlled stretching apparatus synchronized to a digital camera. Our results showed that the in vitro cow lens surface changed in an unexpected manner during accommodation depending upon how much tension was applied to flatten the lens. In this case, the anterior surface collapsed with a reduction in surface initially followed by an increase in surface, when the stretching was applied. In the human lens model, the surface increased when the lens un-accommodated. The lens volume always decreases as the lens flattens. An explanation for the unexpected surface change is presented and discussed. Furthermore, we determined that the changes in lens volume, as reflected by the speed of the equatorial diameter recovery in in vitro cow and rabbit lenses during simulated accommodation occurred within a physiologically relevant time frame (200 ms), implying a rapid movement of fluid to and from the lens during accommodation.