Structure eye & iris reflex

• What is the main focus of today's video?

  The structure of the eye and iris reflex
• What does a cross section of the eye show?

  A view of the inside of the eye
• What is the first structure light hits when entering the eye?

  The cornea
• Why is the cornea transparent?

  To allow all light to pass through
• How does the cornea obtain oxygen?

  By diffusion from the outside air
• What is the function of the cornea?

  To refract or bend light
• What is the iris?

  The colored part of the eye
• What does the iris control?

  The size of the pupil
• What is the pupil?

  A gap in the middle of the iris
• What is the function of the lens?

  To refract or bend light
• How does the lens differ from the cornea?

  The lens can change its shape
• What does the lens help to do?

  Focus light perfectly onto the retina
• What types of receptor cells are in the retina?

  Cone cells and rod cells
• What do cone cells allow us to do?

  See in color
• Why can't we see colors in the dark?

  Only rod cells are working
• What is the fovea?

  A spot on the retina full of cone cells
• What is the function of the optic nerve?

  Transmit impulses to the brain
• What happens to the pupil in bright light conditions?

  The pupil constricts to reduce light
• What is the purpose of the iris reflex?

  To protect the retina from damage
• What are the two types of muscles in the iris?

  Circular muscles and radial muscles
• How do circular muscles affect the pupil in bright light?

  They contract to make the pupil smaller
• What happens to radial muscles in bright light?

  They relax to allow circular muscles to contract
• What occurs in low light conditions regarding the pupil?

  The pupil dilates to let in more light
• How do radial muscles function in low light?

  They contract to pull the pupil open
• What are the steps of the iris reflex in response to light intensity?

  • In bright light, pupils constrict
  • Circular muscles contract
  • Radial muscles relax
  • In low light, pupils dilate
  • Circular muscles relax
  • Radial muscles contract
• What should viewers do if they have thoughts about the video?

  Leave comments down below
• What is the conclusion of the video?

  Hope you enjoyed it and see you soon