Optical Math第 99 / 100 题
How much vertical prism imbalance exists if the reading point is 8 mm below the OC in a +2.50 D right lens and a +1.00 D left lens (Prentice's rule)?
a.0 prism diopters
b.3.5 prism diopters
c.0.8 prism diopters
d.1.2 prism diopters
解析
Each eye's prism = 0.8 cm x power. Right = 0.8 x 2.50 = 2.0; left = 0.8 x 1.00 = 0.8. Both are base-down (plus lens, below OC), so the imbalance = 2.0 - 0.8 = 1.2 prism diopters.
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