Which part of the eye regulates and control the amount of light entering the human eye?

The correct answer is Iris.

Key Points

• The iris is a thin, circular structure in the eye responsible for controlling the diameter and size of the pupil.
• It regulates the amount of light entering the eye by adjusting the pupil size, which is essential for optimal vision.
• The iris contains muscles that contract and expand to adjust the pupil size in response to varying light conditions.
• The color of the iris is what gives the eye its color, varying from blue, green, brown, etc.
• The process by which the iris adjusts the pupil size is known as the pupillary light reflex.

Additional Information

• Retina
  • The retina is the light-sensitive layer at the back of the eye that converts light into electrical signals.
  • It contains photoreceptor cells called rods and cones that detect light intensity and color.
  • The retina plays a crucial role in forming visual images and transmitting them to the brain via the optic nerve.
• Cornea
  • The cornea is the transparent, dome-shaped front layer of the eye that covers the iris, pupil, and anterior chamber.
  • It plays a key role in focusing light onto the retina, contributing to the eye's overall refractive power.
  • The cornea is avascular, meaning it has no blood vessels, and receives nutrients from tears and aqueous humor.
• Pupil
  • The pupil is the black circular opening in the center of the iris that allows light to enter the eye.
  • Its size is regulated by the iris muscles, contracting in bright light and dilating in low light to control light intake.
  • The pupil's adjustment is an essential part of the eye's response to different lighting conditions.