Topic 5 - Eye

• What is the cornea?

  the transparent layer forming the front of the eye that contracts light
• The diagram shows...?


  optic nerve

  
• What is the pupil?

  the gap between the iris which allows light to pass to reach the lens
• What are the names of the two types of receptor cells in the retina?

  rod cells and cone cells
• Which light-sensitive cells in the retina enable you to see in colour?

  Cone cells
• Which light-sensitive cells in the retina enable you to see in black and white and in the dark?

  Rod cells
• The eye is a sense organ. Which two stimuli are the receptor cells of the eye sensitive to?

  light intensity, colour
• What is the purpose of the iris reflex?

  To ensure the optimum amount of light enters the eye
• When the pupil is very large, do we describe it as 'constricted' or 'dilated'?

  constricted
• Which two muscles make up the iris?

  radial muscles and circular muscles
• What happens to the circular and radial muscles when the pupil constricts?

  The radial muscle relaxes and the circular muscle contracts