Further information

As we age our eyes lose their ability to focus quickly on near and far objects. Presbyopia is a common problem that comes with aging, but its causes are not yet fully understood. There is evidence that the crystalline lens inside the eye loses its elasticity and therefore its distance-focusing capabilities. Eye surgeons can replace the stiffened crystalline lens with an artificial implant, such as a multifocal lens that allows the recipient to see near and far objects clearly. That's often done in cataract surgery, but multifocal lenses are not perfect.