Which root means iris?

• A. Iris
• B. Dermat/o
• C. Irid/o
• D. Enter/o

Answer: (C)

In medical terminology, the combining form for the iris is irid/o. This root specifically refers to the iris, the colored part of the eye that governs how much light enters by adjusting the pupil. That’s why irid/o is used to form terms like iriditis (inflammation of the iris) or iridectomy (surgical removal of part of the iris).

The other roots point to different body parts: dermat/o means skin, and enter/o means intestine. While the organ itself is called the iris, the standard combining form used in terms describing it is irid/o, not iris.