Certified Paraoptometric (CPO) Practice Exam 2025

The suffix '-ous' in medical terminology is used to indicate that something is "pertaining to" or "characterized by." This suffix is commonly seen in various medical terms, such as "mucous" (pertaining to mucus) or "nervous" (pertaining to the nerves). It helps to form adjectives that describe qualities, conditions, or relationships related to the root word.

The other choices do not align with the meaning of the suffix. 'Double' would pertain to quantity or multiplicity, 'vision' relates specifically to sight, and 'color' refers to hue or pigment, none of which are represented by the suffix '-ous'. The option indicating "pertaining to" is the most accurate interpretation of that suffix in the context of medical terminology.