**Question:** Refraction in eye not affected by:

A. Iris color
B. Corneal curvature
C. Lens power
D. Intraocular pressure

**Core Concept:** Refraction is the process by which light enters the eye and is bent (refracted) to focus on the retina. In the eye, refraction is primarily governed by the cornea and the lens.

**Why the Correct Answer is Right:** A iris color (determined by pigment concentration) is unrelated to the eye's ability to focus light. While iris color can be used as a patient identifier, it does not influence the eye's refractive power.

**Why Each Wrong Option is Incorrect:**

B. Corneal curvature: Although corneal curvature does affect the overall refractive power of the eye, it does not change the overall refraction during the process. The eye's ability to focus light depends on the cornea and lens, not the iris.
C. Lens power: The lens is the primary component responsible for focusing light within the eye. The lens's power is responsible for the eye's ability to adjust its refractive power (accommodation).
D. Intraocular pressure: IOP (Intraocular Pressure) is the pressure within the eye and does not directly influence the eye's ability to focus light. IOP is a measure of the eye's internal pressure and is unrelated to refraction.

**Clinical Pearl:** Although understanding iris color is important for patient identification, it does not affect the eye's ability to focus light. Corneal curvature is essential for overall refraction but not for the specific process of refraction during focusing. The lens's power is crucial for accommodation, while intraocular pressure does not directly influence the eye's refractive capabilities.

**Correct Answer:** A. Iris color