Refraction of Light in Water Experiment (Video)
Have you noticed that things look a little funny when you see them through a glass of water?
Some of the aberrations are caused by the imperfection in the glass production. But there is more to it.
Refraction is the bending of light as it passes from one transparent medium into another1.
This bending by refraction allows us to make use of lenses, magnifying glasses, prisms, etc.
It also makes it possible for us to see because our eyes use lenses to focus images onto our retina.
Here are two simple and fun water refraction experiments.

Refraction of Light in Water
Here is an easy science experiment you can do to "wow" your kids or friends. It's super simple and you can set it up within minutes.
Materials
- water
- graphics you want to see the changes
Tools
- a clear glass or jar
- adult supervision
Instructions
- Place the glass in front of the graphics.
- Adjust the distance between the glass and the graphics until the image can be seen clearly through the empty glass.
- Slowly pour the water in and see what happens.
Notes
- Do the experiment again using different distances between the glass and the graphics.
- Try glasses and jars of different shapes.
- Try using different liquids such as oil, juice, etc.
Why
Have you noticed that things look a little funny when you see them through a glass of water?
Some of the aberrations are caused by the imperfection in the glass production. But there is more to it.
Refraction is the bending of light as it passes from one transparent medium into another1.
This bending by refraction allows us to make use of lenses, magnifying glasses, prisms, etc.
It also makes it possible for us to see because our eyes use lenses to focus images onto our retina.

When light travels through a cylindrical glass, it bends when entering the glass and water, and then it bends again when leaving the water and glass.
As a result, the light paths cross and the image appears to be flipped horizontally (left/right).

Science Kits And Books On Light
References
- 1.Jiang W, Chen RT, Lu X. Theory of light refraction at the surface of a photonic crystal. Phys Rev B. June 2005. doi:10.1103/physrevb.71.245115