Assertion : A man is blind for some time when he comes out of a well lighted room to a dark place.
Reason : Iodopsin of cone cells is bleached in the presence of strong light.

Options

A. If both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.
B. If both Assertion and Reason are true but Reason is not a correct explanation of the Assertion.
C. If Assertion is true but Reason is false.
D. If both Assertion and Reason are false.

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion**: The assertion states that a man is blind for some time when he comes out of a well-lighted room to a dark place. This phenomenon occurs due to the adjustment of the eyes to the change in light intensity.

2. **Pupil Constriction in Bright Light**: When a person is in a bright environment, the iris muscles contract, leading to the constriction of the pupil. This constriction limits the amount of light entering the eye, which is necessary to prevent damage to the retina from excessive light.

3. **Transition to Darkness**: Upon moving from a bright area to a dark area, the pupils need time to dilate (enlarge) to allow more light to enter. This dilation process takes a few moments, during which the person may experience temporary blindness or difficulty seeing.

4. **Understanding the Reason**: The reason provided states that iodopsin of cone cells is bleached in the presence of strong light. Iodopsin is indeed a photosensitive pigment found in cone cells, which are responsible for color vision and function best in bright light.

5. **Evaluating the Reason**: The statement about iodopsin being bleached is misleading in this context. While it is true that strong light affects iodopsin, it does not directly explain the temporary blindness experienced when moving from light to dark. Instead, the reason for temporary blindness is primarily due to the time required for the pupils to dilate and for the photoreceptor cells to adjust to lower light levels.

6. **Conclusion**: Based on the evaluation, the assertion is true (a person does experience temporary blindness when moving from light to dark), while the reason is false (iodopsin does not directly explain this phenomenon). Therefore, the correct answer is that the assertion is true and the reason is false.

**Final Answer**: The assertion is true and the reason is false.

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