RODENSTOCK OPHTHALMOMETER PATIENT POSITIONING The patient should be seated comfortably behind the instrument. The patient is asked to put their chin in the chinrest and forehead firmly against the forehead rest. The patientís head height should be adjusted by using the sleeve on the vertical bar of the headrest. Adjust the patientís height such that the outer canthus is level with the eye level mark on the right vertical headrest bar. **photo with pt., hand on control with line marked