while comping out from a dark room into bright light we are not able to see for some time. This occurs due to

Options

A. complete bleaching of pigments of bipolar cells
B. deformation of lens proteins
C. Time taken in dilation of pupil
D. Time taken for light adaption

Answer

### Step-by-Step Solution:

1. **Understanding the Scenario**: When we move from a dark room to a bright light, our eyes take some time to adjust. This is a common experience that many people have encountered.

2. **Pupil Response**: In a dark environment, our pupils dilate (enlarge) to allow more light to enter the eyes. This helps us see better in low-light conditions.

3. **Transition to Bright Light**: Upon exiting the dark room, the sudden influx of bright light causes our pupils to constrict (shrink) to reduce the amount of light entering the eye. This constriction is a protective mechanism to prevent damage to the retina from excessive light.

4. **Adaptation Process**: The process of adjusting from darkness to brightness is known as light adaptation. During this time, the photoreceptor cells in our eyes (cones and rods) need to adjust to the new lighting conditions.

5. **Role of Photoreceptors**: Rods are more sensitive to light and are responsible for vision in low-light conditions. When exposed to bright light, these rods can become temporarily non-functional or "bleached," meaning they lose their ability to respond to light until they regenerate their photopigments.

6. **Conclusion**: The inability to see clearly for a short period when moving from dark to bright light is primarily due to the constriction of the pupils and the temporary bleaching of the rod cells in the retina.

### Final Answer:
This occurs due to the deformation of lens proteins and the adaptation of photoreceptor cells in response to the sudden change in light intensity.