The theoretical ideal for an artificial lens implant to correct aphakia

In considering the theoretical ideal for an artificial intraocular lens implant to be used in the correction of aphakia it has always been taken for granted that Nature's bioconvex lens is best. But there is some evidence that other configurations may be an improvement. We also have to decide how large it should be and whether it should be placed in front of the iris or behind it. Moreover we have to consider the management of eyes which are already aphakic when first seen and cataractous eyes requiring lens extraction before the pseudophakos can be inserted.