Science // Waves, Light & Sound

How We See Objects

Develop a model to describe that light reflecting from objects and entering the eye allows objects to be seen

Ages
9 to 11
Type
Concept
Builds on
3 topics
Leads to
2 topics
Standards
3 codes

Quick check

Can the learner draw a diagram showing how light bounces off a book and enters your eye, which is how you actually see the book?

Ask this to see whether the topic is secure.

Topic // Mastery

What mastery looks like

What a learner can do once this topic is secure.
  • Draw a diagram showing light source → light hits object → reflects into eye
  • Explain that we see objects because reflected light enters our eyes, not because our eyes send out light
  • Use this model to explain why we can't see in total darkness (no light to reflect)

Topic // Map

Where this fits

What to learn first and what this topic opens up, with the reason for each link. Required links come first.
  • RequiredMust come first
  • HelpfulHelps, but not essential

Before this

3 topics
  • Reflecting LightRequired

    Waves, Light & Sound // Ages 7 to 8

    Must know light reflects off surfaces before modelling reflection-to-eye vision

  • Wave Behaviour VocabularyRequired

    Waves, Light & Sound // Ages 9 to 11

    Modelling light reflecting from objects into the eye requires reflection vocabulary

  • How Shadows FormHelpful

    Waves, Light & Sound // Ages 7 to 8

    Shadow knowledge supports understanding how light interacts with objects

You are here

How We See Objects

Ages 9 to 11 // Concept

Leads to

2 topics
  • Light Travels in Straight LinesRequired

    Waves, Light & Sound // Ages 10 to 11

    Must understand reflection-to-eye model before using straight-line light to explain how we see

  • White Light & ColourHelpful

    Waves, Light & Sound // Ages 11 to 12

    Prior work on how light reflects into the eye provides context for understanding colour perception

Topic // Research-informed

Teaching notes

From the Marble Skill Taxonomy. These notes have not been validated in classrooms, so treat them as a starting point for your own judgement.

The approach

For ages 9–11, teach that we see a non-luminous object because light travels from a source to the object, reflects off it, and then enters the eye (source → object → eye, one way only). Light sources such as lamps are seen by light travelling directly from them into the eye. The central obstacle is the intuitive extramission belief that something leaves the eye to 'reach out' and see. Surface this belief first with diagnostic drawing/probes, then teach refutationally — name and reject the wrong idea and build the full arrowed ray path — and connect to diffuse reflection so dull everyday objects count as light senders. Because gains often revert, revisit and re-test over time.

Common misconceptions

  • Extramission: the eye sends something out (rays/'visual feelers') to see the object.
  • Light travels both ways — into the eye from luminous things but out of the eye toward non-luminous things.
  • Seeing just requires light to 'land on' and brighten the object; the reflected-into-the-eye step is missing.
  • A whole image or picture of the object flies intact into the eye.
  • Once eyes 'adjust', we can see in complete darkness.
  • Only shiny surfaces reflect light into the eye, so dull objects are seen by some other means.

Useful representations

  • Arrowed ray diagram: source → object → (reflected ray) → eye
  • String or wool physically tracing the light path from lamp to object to eye
  • Camera obscura or a webcam used as a model 'eye' that light enters to form an image
  • Three-holes-in-card or a tube lined up so light only reaches the eye along a straight path

Teaching practices

  • Elicit the child's existing model first with diagnostic probes (e.g. 'draw how you see this book') before teaching — extramission must be surfaced to be challenged.
  • Teach refutationally: explicitly name the wrong idea ('nothing comes out of your eyes — you are not Superman') and contrast it with the correct path, rather than only presenting the right answer.
  • Build and draw the FULL journey with arrowed rays: light source → object → reflected → eye; insist every ray has a direction arrow.
  • Use a physical 'receiver' model so the eye is visibly something light ENTERS: a webcam or camera obscura, or string/wool tracing the path from source to object to eye.
  • Connect to diffuse reflection — ALL surfaces (dull as well as shiny) scatter light into the eye — so that everyday non-luminous objects count as senders of light.
  • Revisit and re-test over weeks: refutational gains on extramission are often short-lived, so one lesson is not enough.

Activities to try

  1. 1

    Make yourself able to see it: route the light path

    Why it works: Seeing is not the eye reaching out; it is light arriving AT the eye after bouncing off the object. If no light reaches the object or no reflected light reaches the eye, the object cannot be seen. Shiny surfaces reflect light mostly in one direction, like a mirror, and dull surfaces scatter it in many directions, so both can send light to the eye.

    1. In an on-screen model of a dark scene with a hidden object (e.g. a mug on a table), take on the goal: 'make yourself able to see it.' (In this model the rays you draw control what can be seen; in real life, drawing arrows does not change what you see.)
    2. First try your own intuition: draw an arrow pointing FROM the eye toward the mug, and notice what happens.
    3. Place a movable lamp and draw a light ray from the lamp to the mug; check whether that alone is enough.
    4. Complete the full chain: lamp → mug → reflected arrow → eye, with a direction arrow on every ray.
    5. Toggle the lamp off and describe what happens to the mug and why.
  2. 2

    Elicit and refute: 'How do you think you can see this book?'

    Why it works: Putting your own theory into words exposes the hidden extramission assumption so it can be named and replaced with the one-way source→object→eye path.

    1. Before any teaching, draw or describe how you see a nearby object such as a book ('draw how you see this book').
    2. Answer a Socratic optician/vision-scientist persona who asks what you think travels, and in which direction, when you look at the book.
    3. When prompted, decide whether anything leaves your eye, and justify your answer.
    4. Re-draw the path after the discussion, adding a direction arrow to every ray.
  3. 3

    Physical receiver model: the eye is something light ENTERS

    Why it works: Because an image only forms when light goes INTO the model eye (camera/webcam/obscura), the eye must be a receiver of light, not a sender; light also travels in straight lines along the traced path.

    1. Use string or wool to physically trace the light path from the lamp to the object and then to the eye position.
    2. Observe a camera obscura or a webcam used as a model 'eye', noticing that an image forms only because light enters it.
    3. Line up three holes in cards (or a tube) so light reaches the eye only along a straight path, and check what happens when one card is shifted out of line.
    4. State in your own words which way the light must be travelling for the image to form.

Topic // Standards

Curriculum standards

Codes for the curriculum statements this topic maps to. Each publisher owns its standard text.
Next Generation Science Standards (NGSS) K-5
4-PS4-2
The national curriculum in England: Key stages 1 and 2 framework document
Y6.Sci.L.2Y6.Sci.L.3

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