Optical MathQuestion 94 of 100
A frame has an A measurement of 52 mm, DBL of 18 mm, and the patient's PD is 62 mm. What is the total decentration for both lenses combined?
a.8 mm per lens
b.0 mm
c.16 mm per lens
d.8 mm total (4 mm per lens)
Explanation
Frame PD (geometric center distance) = A + DBL = 52 + 18 = 70 mm. Total decentration = frame PD - patient PD = 70 - 62 = 8 mm total, split as 4 mm per lens.
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