Top of seg should be at or slightly above the lower pupil margin in normal room illumination. Use Opthalmoscope to view sector via retinal reflex.

Presbylite lenses can rotate up to 30 degrees nasal without visual problems (see OS below). Any temporal rotation requires compensation (see OD below).

Alignment fitting relationship is desired, with a uniform fluorescein pattern along horizontal meridian. Peripheral clearance is also desirable. This pattern should provide unobstructed movement vertically during the blink cycle. High riding lenses should be avoided!