Question

Entering a dark theatre from a bright outer side, it takes few seconds to adjust to the darker theatre for finding the objects inside such as pathway, seats, people, etc. what could be the reason ?

Answer 1

the iris of the eye maintains a balance in the entry of light into the eye. when the retina receives low intensity some time after the pupil's size has been adjusted acc. to bright light, it increases the pupil's size again to allow more light to enter the eye, increasing the clarity in vision.

Answer 2

Answer:

The phenomenon is called Brightness Adaptation

Explanation:

The Human Visual System can Adopt to Enormous Range of Light Intensities.

The Human Vision a night is called Scotopic Vision and the Vision in Bright Light is called Photopic Vision. Cones need High Intensities of light to Activate which is why we can only see colors in DayLight.

In the Intensity vs Subjective Brightness graph, we can see that The transition/ BrightnessChange from Scotopic to Photopic Vision is gradual ( the Curve is less Steep). This is because the eye adjusts the sensitivity slowly by increasing the pupil and Amount of Light Intake.