Optical MathQuestion 100 of 100
A lens has a front curve of +8.00 D and needs +2.00 D total power. What back curve is required (thin-lens approximation)?
a.+6.00 D
b.-6.00 D
c.+10.00 D
d.-2.00 D
Explanation
Total power = front + back. Back = total - front = +2.00 - (+8.00) = -6.00 D. The back surface must be ground to -6.00 D to achieve the +2.00 D lens.
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