Implanting an adjustable PC/IOL will give patients a choice of specific refraction. Target refraction can be achieved by adjustment surgery. When relying only on preoperative biometry, there is no way to escape refractive surprises, as all conceivable methods of preoperative prediction of postoperative refraction are only approximate. Small deviations are usually tolerated by the patients. However, an unwelcome hyperopic refraction or an intolerable refraction constitutes a major reason for PC/IOL exchange. Such IOL explantations may become unnecessary if adjustable PC/IOLs are used. Adjustable IOLs could improve visual results if pseudophakic presbyopia is treated by creating monovision or by multifocal PC/IOLs. After implantation of a mechanically adjustable PC/IOL, a second procedure is only required in case of refractive adjustment, and (in theory) the time of adjustment can be set any time after the PC/IOL has been implanted. In small pseudophakic children, a mechanically and reversibly adjustable PC/IOL may also offer the unique possibility of treating amblyopia and reducing the developing myopia. If necessary, after implantation one could adjust the pseudophakic refraction to create a low degree of myopia. Later, after myopia has increased with growth of the eye, one could conceivably do a second hyperopic adjustment to prevent higher degrees of myopia. This may become the most important application of this concept.