Refraction of light in the eye occurs at :

Options

A. Cornea
B. Lens
C. Iris
D. Aqueous humor.

Answer

To answer the question "Refraction of light in the eye occurs at:", we will analyze the options provided and understand the role of each structure in the eye related to light refraction.

### Step-by-Step Solution:

1. **Understanding Refraction**: Refraction is the bending of light as it passes from one medium to another. In the context of the eye, it is crucial for focusing light onto the retina, where images are formed.

2. **Identifying Eye Structures**: The question provides several options related to parts of the eye:
- **Cornea**: The outermost layer of the eye, responsible for most of the eye's optical power.
- **Lens**: A transparent structure that fine-tunes the focus of light onto the retina.
- **Iris**: The colored part of the eye that controls the size of the pupil and the amount of light entering the eye.
- **Aqueous Humor**: The fluid in the anterior chamber of the eye that helps maintain intraocular pressure and provides nutrients to the eye.

3. **Analyzing Each Structure's Role in Refraction**:
- **Cornea**: The cornea is the primary site for light refraction in the eye. It provides the majority of the eye's total refractive power due to its curved shape and the difference in refractive indices between air and the corneal tissue.
- **Lens**: While the lens also refracts light, its primary role is to adjust focus for near and far objects, refining the image formed by the cornea.
- **Iris**: The iris does not play a direct role in refraction; it regulates light entry.
- **Aqueous Humor**: This fluid does not significantly contribute to light refraction; its role is more about maintaining eye shape and providing nutrients.

4. **Conclusion**: Based on the analysis, the structure where the maximum refraction of light occurs is the **cornea**.

### Final Answer:
The refraction of light in the eye occurs at the **cornea**.

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