The eyes

• What should you be able to name by the end of the video?

  The different parts of the eye
• What is the purpose of the video for triple biology students?

  To explain the functions of the eye
• What is the eye classified as?

  A sense organ
• What do the receptors in the eye detect?

  Light intensity and color
• What is the transparent front part of the eye called?

  The cornea
• What is the function of the cornea?

  To start the focusing of light rays
• What is the space in the center of the iris called?

  The pupil
• What is the role of the iris?

  To control the size of the pupil
• What is the function of the lens?

  To focus light rays onto the retina
• What is accommodation in the context of the eye?

  Changing lens shape to focus light
• What is the back part of the eye called?

  The retina
• What do the receptor cells in the retina detect?

  Light intensity and color
• What do the receptor cells in the retina send to the brain?

  Electrical impulses
• What is the tough outer structure of the eye called?

  The sclera
• What do the ciliary muscles and suspensory ligaments do?

  Help focus on distant or near objects
• What happens to the pupil in low light conditions?

  It becomes larger
• How does the brain respond to low light intensity?

  It sends impulses to iris muscles
• What is the reflex action of the pupil in bright light?

  It becomes smaller
• Why does the pupil become smaller in bright light?

  To reduce light entering the eye
• What are the main parts of the eye and their functions?

  • Cornea: Starts focusing light
  • Iris: Controls pupil size
  • Pupil: Allows light entry
  • Lens: Focuses light onto retina
  • Retina: Contains light receptors
  • Sclera: Protects the eye
  • Ciliary muscles: Adjust focus
• How does the eye adapt to different light conditions?

  • In dim light:
  • Pupil enlarges
  • More light enters
  • In bright light:
  • Pupil constricts
  • Less light enters
• What is the process of accommodation in the eye?

  • Lens changes shape
  • Focuses on distant or near objects
• What is the pathway of light through the eye?

  1. Cornea
  2. Pupil
  3. Lens
  4. Retina
  5. Optic nerve to brain
• What is the difference between the functions of the iris and the lens?

  • Iris: Controls pupil size
  • Lens: Focuses light onto retina
• What should you be able to describe by the end of the video?

  How the eye focuses on objects
• What is the role of the retina in the eye?

  It contains receptor cells sensitive to light
• What part of the eye carries out most of the focusing?

  The cornea
• What is accommodation in the context of the eye?

  The ability to change the lens shape
• How does the ciliary muscle affect the lens during accommodation?

  It changes the thickness of the lens
• What happens when the ciliary muscle contracts?

  The lens becomes thicker and refracts light more
• What occurs when the ciliary muscle relaxes?

  The lens is pulled thin and refracts light slightly
• What is the key fact about focusing on distant objects?

  Light needs to be focused only a small amount
• How does the eye focus on near objects?

  The ciliary muscle contracts to thicken the lens
• What is long-sightedness also called?

  Hyperopia
• What problem do people with long-sightedness face?

  They cannot focus on nearby objects
• Why might someone have long-sightedness?

  The eyeball may be too short
• How can long-sightedness be treated?

  Using glasses with convex lenses
• What is short-sightedness also called?

  Myopia
• What issue do people with short-sightedness experience?

  They cannot focus on distant objects
• What causes short-sightedness in some individuals?

  The eyeball may be too long