Physics of the light and eye

• What are the three possible interactions of light with matter?

  Absorbed, reflected, or transmitted
• What do all electromagnetic waves, including light, do?

  They transfer energy from one place to another
• What occurs during the absorption of light?

  Light rays hit a material and transfer energy to its atoms
• What effect does the absorption of light have on a material?

  It can cause the temperature of the material to increase
• What happens during the transmission of light?

  Light waves strike a material and pass through it
• What determines whether light waves are transmitted or absorbed by a material?

  The wavelength of the light waves
• What occurs during the scattering of light?

  Light waves traveling in one direction are redirected in all directions
• What is the speed of light in empty space?

  No object or wave can move faster than the speed of light in empty space
• How does the speed of light change when it travels through matter?

  It moves more slowly
• What is refraction?

  Refraction occurs when a light ray changes direction moving from one material to another
• What causes light waves to refract?

  Light waves change direction when they change speed moving from one medium to another
• What is white light composed of?

  A combination of all light waves in the visible light spectrum
• How can almost any color of light be created?

  By mixing the three primary colors: red, green, and blue
• What does the law of reflection state?

  The angle of incidence equals the angle of reflection
• What is diffuse reflection?

  Reflection of light rays from a rough surface causing them to go in many directions
• What is regular reflection?

  Reflection from a smooth surface where parallel light rays remain parallel
• How does white light interact with an object?

  Some light is absorbed and some is reflected
• What is the process of transferring light energy to the molecules in a material called?

  Absorption
• Which medium does light travel fastest through?

  Empty space
• Why does an object appear blue?

  It reflects all the other colors except blue
• How does the eye form an image?

  Lenses in the eye focus light to produce an image on the back of the eye
• What is the function of the retina?

  It contains light-sensitive cells that convert the image into electrical signals
• What is the cornea?

  A clear area of the sclera that light enters through
• What is the role of the iris?

  It expands and contracts to control the amount of light entering the eye
• What do ciliary muscles do?

  They control the shape of the lens as they contract and relax
• What are rod cells responsible for?

  Responding to dim light
• What do cone cells enable you to see?

  Colors
• How do cone cells respond to different wavelengths of light?

  They cause you to see objects as having color
• What determines the color of a pigment?

  The wavelengths of the light it reflects
• What is the primary function of pigments?

  To change the color of other materials or objects
• What are the main components of the eye and their functions?

  • Cornea: clear layer that bends light rays
  • Lens: transparent structure that focuses light
  • Iris: controls light entry by expanding and contracting
  • Retina: contains light-sensitive cells (rods and cones)
  • Optic nerve: carries signals to the brain
• What are the types of cone cells and their responses?

  • One responds to red and yellow light
  • One responds to yellow and green light
  • One responds to blue and violet light
• What are the differences between regular and diffuse reflection?

  • Regular reflection: smooth surface, parallel light rays remain parallel
  • Diffuse reflection: rough surface, light rays scatter in many directions