Certified Paraoptometric (CPO) Practice Exam 2025

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

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!

Practice this question and more.

Which lens material is described as being much harder to break or shatter?

CR-39
Trivex
High-Index Lenses
Glass

The correct answer is: Trivex

Trivex is known for its exceptional impact resistance and durability, making it much harder to break or shatter compared to other lens materials. This characteristic is particularly important for safety glasses and lenses designed for active lifestyles. Trivex not only provides strong impact resistance but is also lightweight, contributing to comfort while maintaining optical clarity. Other lens materials, while offering certain advantages, do not match Trivex in terms of shatter resistance. For example, CR-39 is a popular plastic lens material known for its optical clarity and light weight, but it is not as impact-resistant as Trivex. High-index lenses, designed for thinner profiles in higher prescriptions, have their own benefits but can also be more susceptible to breaking compared to Trivex. Glass lenses, though they provide excellent optical quality and scratch resistance, are actually more likely to shatter upon impact, which poses a safety risk.