Prescription Analysis第 52 / 100 题
A spherical equivalent of the Rx -2.00 -1.00 x 180 is what?
a.-2.50 D
b.-3.00 D
c.-1.50 D
d.-2.00 D
解析
Spherical equivalent = sphere + one-half the cylinder = -2.00 + (-1.00 / 2) = -2.00 + (-0.50) = -2.50 D. It represents the average dioptric power of the lens.
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