Diagnostic instruments, systems and methods for performing measurements on eyes are disclosed. In one embodiment of the instrument, a left ocular is disposed in a portion of a left visual path for the left eye, the left ocular positioned to permit the left eye to view a target, a right ocular is disposed...http://www.google.de/patents/US7425067?utm_source=gb-gplus-sharePatent US7425067 - Ophthalmic diagnostic instrument
