A US patent application made public on Thursday hinted that Apple may be toying with the idea of letting picture-loving iPhone users change lenses for the smartphone cameras. Apple\'s application for a \"back panel for a portable electronic device with different camera lens options\" included a diagram reminiscent of an opened iPhone with labeled parts. The application described a design to let users change lenses that typically are fixed in the backs of smartphones to act as eyes for cameras. \"It would be desirable to provide a structure for a compact device that allows the end user to reconfigure the optical arrangement of the device while retaining the benefits of assembling the device using a pre-assembled digital imaging subsystem,\" said a copy of the patent application available online.