21
11625-101-Rev. L
Instructions for Use
(continued)
Taking Measurements
(continued)
Near Tests
1. All tests for near (dynamic retinoscopy,
amplitude of accommodation, dynamic
cross cylinder, positive and negative
relative accommodation, phorometry) are
generally made with the Vergence Levers
in the inward (converged) position.
Refer to Figure TM-2.
2. With a distance PD of 64mm, moving both
levers from the extreme outward position
to the extreme inward position converges
the instrument apertures for the near test
at 16 inches. At the same time, aperture
separation is decreased by 4mm.
3. For PD settings greater than 64mm, the
instrument apertures are slightly under
converged; reducing the PD adjustment
by 1mm or less compensates for it.
4. For PD settings less than 64mm, the instrument apertures are slightly over converged; this is
corrected by slight outward adjustment of the levers.
Note:
Do not attempt to fully converge the instrument below 55mm distance PD.
Figure TM-2 Vergence Levers In (Near Tests)
