| 摘要 |
An apparatus and method for subjectively (and in some cases at least partially objectively) determining the proper positioning of progressive power or other corrective lenses are disclosed. The apparatus includes a target such as a small fiber optic or other light source and one or more marking rods which may be activated by the patient (or, in some cases, by the practitioner). While wearing pre-fitted frames and fixating on a remote target, the patient (or practitioner) places the light source against or immediately adjacent the exterior surface of the simulated or other lens within either of the frames and positions the light so that it is centered in the patient's line of sight. Once the light is centered the marking rod is activated which contacts, and marks, the exterior surface of the lens. Because in some embodiments of the apparatus the light source and marking rod or rods are designed to obstruct very little of the patient's vision, his or her peripheral vision remains intact during the process, thereby allowing binocular fusion to occur and avoiding introduction of phoria errors into the positioning process. Other embodiments omit the marking rods but can be attached (temporarily) to the pre-fitted frames for later marking using conventional markers. |
