A person with limited accommodation is prescribed lenses of power -1.0 diopters for distant vision.Bifocal inserts are added to these lenses to allow vision at 30 cm.What is the power of the inserts?
A)2.3 diopters
B)3.3 diopters
C)4.3 diopters
D)This does not work with negative diopter distance lenses.

Question

Quizplus · Accepted Answer

The power of the bifocal inserts can be calculated using the formula:
Power of inserts = (1/focal length of inserts) - (1/focal length of distance lenses)
The focal length of distance lenses is -1.0 diopters, which means the focal length is -1 meter.
To find the focal length of inserts, we can convert the distance of 30 cm to meters: 
Focal length of inserts = 0.3 meters
Now, we can substitute these values into the formula:
Power of inserts = (1/0.3) - (-1) = 3.3 diopters
Therefore, the correct answer is (B) 3.3 diopters.

A Person with Limited Accommodation Is Prescribed Lenses of Power