When we move from dark to light, we fail to see for some time but soon the visibility become normal. It is

Options

A. Accomodation
B. Adaptation
C. Mutation
D. Photoperiodism

Answer

To solve the question, we need to understand the phenomenon that occurs when we transition from a dark environment to a bright one, and why our visibility is affected initially but then normalizes.

### Step-by-Step Solution:

1. **Understanding the Scenario**: When we move from a dark place to a well-lit area, our eyes initially struggle to see clearly. This happens because our eyes are not immediately adjusted to the new light intensity.

**Hint**: Think about how our eyes react to sudden changes in light.

2. **Role of Photoreceptor Cells**: The human retina contains two types of photoreceptor cells: rods and cones. Rods are sensitive to low light levels and are responsible for night vision, while cones function best in bright light and are responsible for color vision.

**Hint**: Recall the functions of rods and cones in different lighting conditions.

3. **Adaptation Process**: The process of adjusting to different light levels is known as adaptation. When we move from darkness to light, our eyes undergo a rapid adjustment where the cones become more active to handle the increased light intensity.

**Hint**: Consider what happens to our vision when we are exposed to bright light after being in the dark.

4. **Conclusion**: The reason we initially fail to see clearly in bright light but then regain normal visibility is due to the adaptation of our eyes to the new light conditions. This process allows us to see clearly again.

**Hint**: Focus on the term that describes the adjustment of our eyes to different light intensities.

### Final Answer:
The correct answer to the question is **B. Adaptation**.