Certified Paraoptometric (CPO) Practice Exam 2025

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Prepare for the Certified Paraoptometric (CPO) Exam 2025. Study with flashcards and multiple-choice questions, each question has hints and explanations. Get ready for your exam!

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What is the most commonly used ophthalmic dye available in liquid form?

  1. Sodium Fluorescein

  2. Carbonic Acid

  3. Phenylephrine

  4. Timolol

The correct answer is: Sodium Fluorescein

Sodium Fluorescein is widely used as an ophthalmic dye due to its effectiveness in a variety of diagnostic procedures, including the assessment of the corneal integrity and the evaluation of tear film dynamics. The bright green color it produces under blue light makes it highly visible and easy to interpret during examination. In contrast, carbonic acid is not an ophthalmic dye and is more commonly associated with metabolic processes. Phenylephrine is a mydriatic agent used to dilate the pupil, and timolol is a beta-blocker prescribed primarily for the treatment of glaucoma. These latter options do not serve the function of a diagnostic dye and are not available in a liquid form specifically for staining in ophthalmic applications.