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Year 11 Science — The human eye and the colourful world

Name the parts of the eye and what each does, tell myopia from hypermetropia and pick the lens that corrects each, and explain dispersion, twinkling and the blue of the sky by refraction and scattering.

Name: ________________________

  1. 1.Why does the sky look dark to a passenger flying very high up?

    • a) The Sun is closer and outshines the sky
    • b) The air is colder and refracts less
    • c) The window glass absorbs the blue light
    • d) There is too little scattering at that height

  2. 2.Newton passed his spectrum through a second identical prism placed upside down, and got white light out again. What did that show him?

    • a) Sunlight is made up of the seven colours the first prism separated
    • b) The second prism destroyed the colours
    • c) The first prism had added colours to the light
    • d) A prism can bend light but not split it

  3. 3.Someone needs both distant and near vision corrected and is given bi-focal lenses. What is in the upper portion?

    • a) A concave lens, for near vision
    • b) A convex lens, for near vision
    • c) A convex lens, for distant vision
    • d) A concave lens, for distant vision

  4. 4.Match each part of the eye to what it does.

    • The cornea
    • The iris
    • The pupil
    • The retina
    • The ciliary muscles
    • The optic nerve
    • Controls the size of the pupil
    • Carries the signals to the brain
    • Regulates how much light gets in
    • The light-sensitive screen the image falls on
    • Change the curvature of the lens
    • Where most of the refraction happens

  5. 5.For a young adult with normal vision, what are the near point and the far point?

    • a) About 25 cm, and infinity
    • b) About 25 cm, and a few metres
    • c) Zero, and infinity
    • d) About 2 m, and infinity

  6. 6.Why is a clear sky blue?

    • a) Fine particles and air molecules scatter short blue wavelengths more strongly than long red ones
    • b) The sea reflects its colour up into the sky
    • c) Blue light travels faster through air than red light does
    • d) The atmosphere is made of a blue gas

  7. 7.Atmospheric refraction makes the Sun visible about 2 minutes before it actually rises, and keeps it visible about 2 minutes after it actually sets. How many extra minutes of sunlight is that in a day? Answer with a number.

  8. 8.A prism throws a spectrum onto a screen. Put the colours in the order the chapter gives them, starting with "Violet".

    • Yellow
    • Orange
    • Indigo
    • Green
    • Blue
    • Violet
    • Red

Answer key — Year 11 Science — The human eye and the colourful world

  1. 1. d) There is too little scattering at that height
  2. 2. a) Sunlight is made up of the seven colours the first prism separated
  3. 3. d) A concave lens, for distant vision
  4. 4. The cornea → Where most of the refraction happens; The iris → Controls the size of the pupil; The pupil → Regulates how much light gets in; The retina → The light-sensitive screen the image falls on; The ciliary muscles → Change the curvature of the lens; The optic nerve → Carries the signals to the brain
  5. 5. a) About 25 cm, and infinity
  6. 6. a) Fine particles and air molecules scatter short blue wavelengths more strongly than long red ones
  7. 7. 4
  8. 8. 1. Violet 2. Indigo 3. Blue 4. Green 5. Yellow 6. Orange 7. Red