Why can you not see objects in a dim lit room when you come from a brightly lit room?

The correct answer is The iris contracts the pupil to allow less light to enter the eye.Key Points

• When we move from a brightly lit room to a dimly lit room, our eyes take some time to adjust to the change in lighting.
• This is because the iris, which controls the amount of light entering the eye, needs to adjust to the new lighting conditions.
• This helps to improve the clarity of the image that is formed on the retina.
• Dilation of the eye lens actually allows more light to enter the eye, and so this would not help in a dimly lit room.​

Additional Information

• Iris:
  • The iris is a circular muscle in the eye that controls the size of the pupil and the amount of light entering the eye.
  • It is responsible for adjusting the amount of light that enters the eye based on the lighting conditions.
• Pupil:
  • ​The pupil is the black circular opening in the center of the iris that allows light to enter the eye.
  • Its size is controlled by the iris, which adjusts it based on the amount of light available.
• Vitreous humour:
  • The vitreous humour is a gel-like substance that fills the eye and helps to maintain its shape.
  • It does not have any control over the amount of light entering the eye.
• Cornea:
  • The cornea is a transparent layer at the front of the eye that helps to focus light onto the retina.
  • It does not have any control over the amount of light entering the eye.