Joints and muscles – Clip

The iris is an involuntary muscle that controls the pupil size in the eye. It adjusts by contracting and relaxing to regulate the amount of light entering the eye, aiding in clearer vision.

What role does the iris play in the eye?

• It produces tears.

• It focuses light onto the retina.

• It controls the size of the pupil.

• It detects color.

How do the iris muscles help in vision?

• By producing visual pigments.

• By adjusting the amount of light entering the eye.

• By changing the shape of the lens.

• By filtering harmful UV rays.

What happens when the iris muscles contract?

• The eye color changes.

• The pupil becomes smaller.

• The lens becomes thicker.

• The pupil becomes larger.

Why is it important for the iris to adjust the light entering the eye?

• To reduce eye strain.

• To change eye color.

• To improve clarity of vision.

• To enhance night vision.

What is the primary function of the pupil?

• To focus light onto the retina.

• To regulate the amount of light entering the eye.

• To produce tears.

• To detect motion.