Question

The visible coloured ring of the eye is called:

• A. \( \text{Lens} \)
• B. \( \text{Retina} \)
• C. \( \text{Cornea} \)
• D. \( \text{Iris} \)

Hint:

The color of the iris is determined by the amount and type of pigment (melanin) it contains. It varies among individuals and can range from brown to blue, green, or gray.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
The question asks for the structure that is both visible from outside the eye and responsible for its color.

Step 2: Key Formula or Approach:
Check each structure on two points together: is it visible from outside, and does it carry pigment. Only a structure that passes both checks can be the answer.

Step 3: Detailed Explanation:
The cornea is visible from outside but is completely clear, so it carries no pigment of its own. The lens sits deeper inside the eye behind the iris and is also transparent. The retina lies at the very back of the eyeball, completely hidden from outside view.
The iris sits right behind the clear cornea, so light passing through the cornea reveals the iris underneath. It contains pigment cells called melanocytes, and the amount and type of pigment determine whether the eye looks brown, blue, green, or hazel. It also has muscle fibers that widen or narrow the pupil at its center.

Step 4: Final Answer:
Since the iris is the only structure that is both visible through the clear cornea and pigmented, it is the part that gives the eye its color.