Certified Paraoptometric (CPO) Practice Exam 2025

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

Gear up for the Certified Paraoptometric (CPO) Exam 2025. Study with interactive quizzes and multiple-choice questions with comprehensive explanations. Excel in your exam with our tailored preparation tools!

Start Multiple Choice Practice Test
Start Flash Cards

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 role does the ciliary muscle play in vision?

  1. Helps maintain the shape of the eyeball

  2. Controls eye movement

  3. Alters the shape of the crystalline lens

  4. Regulates light entering the eye

The correct answer is: Alters the shape of the crystalline lens

The ciliary muscle plays a crucial role in altering the shape of the crystalline lens, which is essential for focusing light onto the retina. When the ciliary muscle contracts, it causes the tension in the zonular fibers to decrease, allowing the lens to become thicker and more curved. This increased curvature is necessary for focusing on near objects, a process known as accommodation. Conversely, when the ciliary muscle relaxes, the lens flattens for distance vision. This ability to change shape enables clear vision at various distances, making the ciliary muscle integral to our visual acuity.

More Questions Like This