Certified Paraoptometric (CPO) Practice Exam 2025

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Prepare for the Certified Paraoptometric Exam with our comprehensive quiz featuring multiple-choice questions. Each question is accompanied by hints and explanations, helping you build your knowledge and confidence. Get ready to excel in your career!

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!

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Which lens material is typically less scratch-resistant than glass?

CR-39
Polycarbonate
Trivex
Glass

The correct answer is: CR-39

CR-39 is indeed typically less scratch-resistant than glass. It is a plastic material that is lightweight and offers good optical clarity, but it does not have the same level of hardness as glass, making it more susceptible to scratches. While polycarbonate and Trivex also offer significant advantages like impact resistance, they too are less scratch-resistant compared to glass unless they are treated with a hard coating. Glass lenses, on the other hand, have a more durable surface that is less prone to scratching, which makes them ideal for those who prioritize scratch resistance in their eyewear. This understanding of lens materials and their respective properties is essential for ensuring that patients receive the most suitable eyewear based on their needs and lifestyle.