Light can act in peculiar ways in certain circumstances and can at times, twist our vision. There’s a lot of different “illusions” that can be caused by light manipulation and today we’re going to explore a simple example of this. This is the Light Refraction experiment, a very easy to do activity that can be done at home with kids! In order to perform this experiment, you’ll need a few easy to obtain items: You will need:
  • Water
  • A clear empty bottle
  • Something to write on (such as card or paper)
  • Something to write with (such as a pen or marker)


  • This experiment is very simple, but can be tested out in a lot of ways. One way we recommend doing things is writing a “backwards” message on some card or paper. If you’re unsure of how to do this, try to reference the image on the right. Alternatively, you can keep things simpler by just making a drawing instead.
  • Next, fill your bottle up to the top with water. If the bottle has any labels on it, take them off as you’ll need to see through the bottle for the experiment to work.
  • Depending on your lighting, the next part may be a little tricky. Essentially you’ll want to stand your written down message or drawing behind the bottle of water so that you have to look through the bottle of water to see what you wrote down.
  • Adjust the angle and positioning until you see an inverted image of what you wrote down on the card or paper. If you wrote down a “backwards” message beforehand, it should now appear flipped through the bottle and become readable. And that’s a simple take on the Light Refraction experiment – now let’s learn how it works!
The Science Bit: Much like sound, light rays travel at different speeds through different substances. This change in speed actually bends light when passed from one medium to another, which we call “refraction”. In this case, the light travels through the air first, then through the water in the bottle and then back through the air and finally into our eyes. This result of this is a magnifying glass type of effect on what you wrote on the piece of card or paper and at certain angles, you may see an inverted image of what was written down. Another factor in this is the distance between the image and the bottle, this is because the bottle acts as a “convex lens”, which bends light to a focal point. If you move the image too close to the bottle, it’ll appear as normal. However if you go beyond the focal point, you should see the effects from the refraction.

Run Your Own Fun Science Branch

A Fun Science franchise is perfect if you want to run your own business without the risks and hassle of starting up alone. Interested? Then click the link for more information!

Waterloo House, Dominion Rd,
Twerton, Bath BA2 1DW