Certified Ophthalmic Assistant Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Study for the Certified Ophthalmic Assistant Exam. Access multiple choice questions that reflect actual exam content and receive hints and explanations for each question. Prepare effectively and embark on your path to certification!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What is the power of a lens with a focal length of 2 meters?

2D
1D
0.5D
0.25D

The correct answer is: 0.5D

The power of a lens is calculated using the formula: power (P) in diopters (D) is equal to 1 divided by the focal length (f) in meters. Thus, if the focal length of the lens is 2 meters, the calculation would be: P = 1 / f = 1 / 2 = 0.5 D. This means that the lens has a power of 0.5 diopters, which indicates it is a weak converging lens. The power is inversely related to the focal length; longer focal lengths yield lower power values. Hence, the correct answer is that the power is 0.5D.