American Board of Opticianry (ABO) Practice Test

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

Prepare for the ABO certification with our comprehensive test preparation resources. Engage with interactive quizzes and detailed questions created specifically for the ABO exam. Enhance your understanding of opticianry concepts and ace your certification test!

Practice this question and more.

Where is prism verified in Progressive Addition Lenses (PALS)?

a. At the dot beneath the fitting cross
b. Down
c. Apex of the cornea
d. Vertex compensation formula

The correct answer is: a. At the dot beneath the fitting cross

Prism verification in Progressive Addition Lenses (PALS) is typically done at the dot beneath the fitting cross. This is because the fitting cross represents the reference point for fitting the lenses on the patient's face, and the dot beneath it is used to mark the optical center of the lenses. The other options are incorrect because - B: "Down" is a vague term and doesn't specify a specific location for prism verification. - C: The apex of the cornea is not relevant for prism verification, as it is used for fitting regular single vision lenses. - D: The vertex compensation formula is used to calculate prism power, but it is not the location where prism is verified.