Certified Paraoptometric (CPO) Practice Exam 2025

What does the term "DBL" refer to?

1. Distance Between Lenses

2. Diameter of the Bridge Length

3. Depth Below Lenses

4. Distance Between Legs

The correct answer is: Distance Between Lenses

The term "DBL" refers to "Distance Between Lenses," which is a crucial measurement in eyewear fitting. This measurement determines the space between the inner edges of the lenses in a pair of glasses, ensuring proper alignment with the wearer’s pupils. Accurate DBL measurement is essential for providing optimal visual comfort and ensuring that prescriptions are properly positioned, which helps to avoid visual distortions and enhances the effectiveness of the lenses. Other options, while they contain relevant concepts related to eyewear and lens fitting, do not accurately define the term "DBL." For instance, "Diameter of the Bridge Length" may describe a different aspect of glasses but doesn't align with the commonly accepted meaning of DBL in optometry. Similarly, "Depth Below Lenses" and "Distance Between Legs" refer to different metrics that are not associated with the definition of DBL.