If there is no light, there is no sight – explore our resources and learn more about the basics of light, how we see and how we perceive the world around us. The research work of three scientists is also profiled – they are working in the areas of optics, ophthalmology and biophotonics.

Learn about the basics of light and how it behaves:

  • How is light produced? What is light made up of? How does light travel through space? Find out more in the article Light basics.
  • When blue light, red light and yellow light are mixed, white light results, but when blue, red and yellow paints are mixed, the resulting paint is a dark brown. We explain this apparent confusion in the article Colours of light.
  • Apart from looking directly at a light source, most of what we see is as a result of the process of reflection. We look at the main principles of reflection in the article Reflection of light.
  • Light in a vacuum travels at a constant speed of 300,000 km/s. Its speed in media like air, water and glass is slightly slower. It is this change of speed that lies behind the phenomenon known as refraction. Discover more about the bending of light by refraction.
  • Explore a timeline to discover key advances in ideas about light, how we see and how we perceive the world around us.

We also investigate how we see.

Most people have some understanding of how we see things, but there is more to it than meets the eye. Find out about the conflicting theories that surround the eye’s ability to focus on objects as well as how the eye can transform light energy into electrical energy.

Both of our eyes allow us to see in 3D, but does this mean that people with only one eye can only see in 2D? Find out more about depth in visual perception and seeing in 2D and 3D in the artice Depth perception.

Meet the scientists

We profile three scientists working in this field.

Take up the challenge

Student activities include a mix of hands-on and literacy-based investigations. Consider beginning a teaching sequence with Light and sight: true or false? The activity is supported by the teacher resource Alternative conceptions about light and is a useful pretest to establish student understanding.

Students who like to build models will enjoy these very effective activities to explore the basics of light: Investigating reflection, Investigating refraction and spearfishing and Pinhole cameras and eyes.

The Question dice game and Angle of refraction calculator challenge provide opportunities for students to practice literacy and numeracy skills.

Key terms

For explanations of key concepts, see Light and sight – key terms.

    Published 28 March 2012, Updated 28 February 2017