Practice Test Geeks(CPOA) Certified Paraoptometric Assistant Practice Test
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Ophthalmic Optics Flashcards

7 cards from real CPOA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Ophthalmic Optics flashcards as text

  1. What does the addition (ADD) power in a bifocal or progressive prescription represent?

    Answer: The extra plus power added to distance Rx for near vision

    The ADD power is the additional plus power added to the distance prescription to bring near objects into focus for presbyopic patients.

  2. Which lens material has the highest Abbe value among commonly used ophthalmic lens materials?

    Answer: CR-39 plastic

    CR-39 plastic has an Abbe value of approximately 58, which is the highest among common ophthalmic materials, meaning it produces the least chromatic aberration.

  3. A patient complains of 'swim' or image movement when they move their head while wearing new progressive lenses. This is most likely caused by:

    Answer: Peripheral distortion inherent to progressive lens design

    Progressive addition lenses have areas of peripheral distortion and aberration that can cause a 'swimming' sensation, especially during adaptation.

  4. What is the optical significance of the geometric center versus the optical center of a lens?

    Answer: The optical center is where prism power is zero; the geometric center is the physical middle of the lens

    The optical center is the point through which light passes without prismatic deviation, while the geometric center is simply the physical middle of the lens blank.

  5. When dispensing high minus lenses, which edge treatment is most important for cosmetic and comfort reasons?

    Answer: Roll and polish or bevel the thick edge

    High minus lenses are thickest at the edges, so rolling and polishing (or proper beveling) improves cosmetics and reduces the 'ring' appearance of thick edges.

  6. What does 'aspheric' mean in reference to ophthalmic lens design?

    Answer: The lens surface curves gradually change to reduce peripheral aberrations

    Aspheric lenses have surfaces that gradually flatten toward the periphery, reducing spherical aberration and allowing for thinner, flatter lens profiles.

  7. Photochromic lenses darken in response to which type of radiation?

    Answer: Ultraviolet radiation

    Photochromic molecules in these lenses are activated by ultraviolet radiation, causing the lens to darken; they lighten indoors where UV is absent.