I love doing science experiments with my kids that require minimal household material , are easy to set up and inspire discovery, learning and playing. This DIY magnifying glass is one such project that will astound children and adults alike.
We were first inspired to do this experiment after watching the Curious George – Great Monkey Detective show when my eldest son was a little boy. In the episode, George tries to investigate things using a clear glass rolling pin filled with water. Today, I just happen to realize that I never did this experiment with my younger son, so it was time to revisit it again. The kids loved it and had fun looking at things in the backyard with their own DIY magnifying glass.
Watch the Experiment here
Materials for DIY Magnifying Glass
- Clear plastic bottle
- Water
- Scissors / X-acto Knife
- Marker

Mark a circle shape near the neck of the bottle.

Cut the circle shape. It needs to be close to the bottle’s neck so you get a disc shape once you cut it out.

Pour a little water into the disc and your magnifying glass is ready.

Hold it over a book or paper to make the letters appear bigger. It’s really that simple and actually works.

How It Works
When the water is put on the plastic disc, it acts as a convex lens. Convex lens is a thick centered lens with a thinner edge and can magnify objects if you look through it. A water droplet surface curves outwards to form a dome. The outward curvature of the water droplet is similar to the curved surface of a convex lens. The more outwardly curved the lens, the stronger its magnification. This is because it is bending or refracting more light in a shorter space. The effect is an enlarged image on your eye. The object seems larger than it is.
What do you think will happen if the water drop is smaller ? It will create a bigger shift in the direction of the light ray, hence a larger magnification.
Changing the position of the water drop with respect to the letters and your eye will also affect the magnification factor. So, if you are wondering why you do not have a clear picture. Then try adjusting the distance between the magnifier and the object.
Further Extension
- You can also create a magnifying glass by filling a clean glass jar with water to the top and and watch the objects magnify by looking through the jar.
- Try replacing water droplets with any other clear liquid.
- Experiment how magnification changes with different sized water droplets.
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Here are some more science experiments to try
Very interesting. I never thought that you could make a magnifying glass at home. Thank you, my son would love this.
I am glad you liked it. It is so quick to put together and brings load of excitement and exploration for kids.
I loved the magnifying glass but water will fall if i use it for a diy projector please help me make a projector
To make a diy projector, cut two disc shape of same size from the plastic bottle, hot glue them together on top of each other like this (). Leave a small gap and then using a syringe add water inside it and close it by gluing it. That way water wont fall out of it and you should be able to use it for a projector. I hope that helps.