ELECTRONIC DEVICE SYSTEM WITH SUPPLEMENTAL LENSES

A head-mounted device may have a display that displays content for a user. Head-mounted support structures in the device support the device on the head of the user. A non-removable lens system may be supported by the head-mounted support structures. The head-mounted support structures may be configured to receive a removable supplemental lens system. The removable supplemental lens system may be used to customize the head-mounted display to accommodate the user's vision. Information such as information on the optical characteristics of the removable supplemental lens system and the user's eyeglass prescription may be stored in the removable supplemental lens system using bar codes, text, programmable memory, or other data storage. When the removable supplemental lens system is installed in the head-mounted device, control circuitry in the head-mounted device may retrieve the stored information. A gaze tracker system or other sensors may be used in retrieving the stored information.