Why does it take some time to see objects in a cinema hall, when we just enter the hall ?

Explanation

**Step-by-Step Solution:**

1. **Understanding Light Conditions**: When you enter a cinema hall, the lighting conditions are significantly different from the outside environment. Typically, the cinema hall is much darker than the area you were in before entering.

2. **Pupil Adjustment**: The human eye has a mechanism to protect itself from excessive light. When you are in a brightly lit area, your pupils constrict (become smaller) to limit the amount of light entering the eye. This helps prevent damage to the retina.

3. **Transition to Darkness**: Upon entering the dark cinema hall, the amount of light available is much lower than what your eyes are used to. The pupils, which were constricted in the bright light, need to adjust to this new environment.

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