Human eye is adjusted for distant objects more than 6 m away. For seeing the near objects which of the following would not occur ?

Options

A. Contraction in circular ciliary muscle
B. Slackening of suspensory ligaments
C. Radius of curvature of lens decreases
D. Decrease in curvature of the lens

Answer

To solve the question regarding the adjustments of the human eye for distant and near objects, we need to understand the physiological changes that occur in the eye during these two types of vision.

### Step-by-Step Solution:

1. **Understanding Far Vision**:
- When the human eye is focused on distant objects (more than 6 meters away), the eye is in a relaxed state.
- In this state, the **ciliary muscles** are relaxed, which means they do not exert tension on the lens.
- The **suspensory ligaments** (zonules) are stretched due to the relaxed ciliary muscles, which increases the focal length of the lens. This elongation allows the lens to focus light from distant objects onto the retina.

2. **Understanding Near Vision**:
- For near vision, the eye must adjust to focus on objects that are closer than 6 meters.
- In this case, the **ciliary muscles** contract, which reduces the tension on the suspensory ligaments.
- As a result, the **suspensory ligaments** become slackened, allowing the lens to become more rounded or oval-shaped, which decreases the focal length. This adjustment enables the eye to focus on nearby objects.

3. **Identifying What Would Not Occur**:
- The question asks which of the following conditions would **not** occur when seeing near objects.
- We analyze the options:
- **Contraction of ciliary muscles**: This occurs during near vision.
- **Slackening of suspensory ligaments**: This also occurs during near vision.
- **Decrease in radius of curvature of the lens**: This occurs during near vision as the lens becomes more rounded.
- **Decrease in curvature of the lens**: This would imply that the lens is becoming flatter, which does not happen during near vision; instead, the curvature increases.

4. **Conclusion**:
- The condition that would **not occur** when seeing near objects is the **decrease in curvature of the lens**. Instead, the curvature increases to allow for better focus on nearby objects.

### Final Answer:
The condition that would not occur when seeing near objects is **decrease in curvature of the lens**.