light — Year 3 Science

Year 3 light: what pupils learn

Year 3 light teaches pupils that we see because light reaches our eyes, not because objects simply glow, and introduces shadows as a visible effect of light being blocked.

By the end of Year 3, the National Curriculum expects pupils to:

• recognise that they need light in order to see things, and that dark is the absence of light
• notice that light is reflected from surfaces
• recognise that light from the sun can be dangerous, and know ways to protect their eyes
• recognise that shadows are formed when light from a light source is blocked by an opaque object
• find patterns in the way the size of shadows change

Key vocabulary

light, light source, dark, reflect, surface, opaque, transparent, translucent, shadow

How it builds

Year 3 is pupils’ first dedicated light topic. The ideas about shadows and reflection return at Key Stage 3, where light is studied in terms of rays, angles of reflection, and how lenses and mirrors work.

Frequently asked questions

Why can’t we see in a completely dark room?
We see objects because light bounces off them and travels into our eyes. With no light source at all, there is nothing to reflect, so nothing reaches our eyes.

Why does a shadow change size during the day?
The Sun’s position in the sky changes, which changes the angle the light hits an object from, making shadows longer when the Sun is low and shorter when it is high.

Is it ever safe to look directly at the Sun?
No, never, even briefly or through sunglasses. It is never safe to look directly at the Sun, which is why we teach children to look at its effects (like shadows) rather than at the Sun itself.

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