Playing detective is one of my little ones' favourite games, but to be a real detective, you need lots of science! So today, we're going to make a magnifying glass.
This activity is part of my playful science series, so don't forget to check out the other simple science ideas too!
How to Make a Magnifying Glass
Materials
A clear plastic bottle
A dry marker pen
A pair of scissors
Water

How to make a magnifying glass
1. Draw a circle at the neck of the bottle. It needs to be on the neck so that when you cut it out, it will create a disc shape.

2. Cut out the circle
3. Pour a little water into the disc.

4. Hold it over your book or paper to make the letters bigger. It works really well!

Why does this work?
The disc shape you have cut out curves outwards. It is a convex shape. By adding the water, the light that passes through is refracted. This means it is bent inwards, creating a lens effect enlarging the size of the letters. You now have your very own magnifying glass!
Last Updated on March 18, 2025 by Emma Vanstone
HELEN says
wow, very clever indeed!
Julie says
So cool! We are definitely going to try this. Thanks
Susan Case says
Brilliant! Love it.
Ann says
That is such a neat idea - can't wait to try this out with the kids!
Crafty Little People says
Simple but effective! My kids would love this.
Deborah says
Oh yes, this is super cool! I better run and dig those bottles out of the trash can:)
Carrie says
Oh, how neat!! My daughter would love this. We will definitely have to give it a try. Thank you for sharing at Sharing Saturday!! I hope you are having an amazing week!
Oh, and on another note, have you seen the latest issue of Family Fun Magazine? They have a craft/activity very similar to your lung one. I thought of you when I saw it.
ScienceSparks says
Let us know if you try it. Is Family Fun online?
Benjamin says
Everyone says this is great for the kids, i am 25 and i LOVE this. Its so cool, making your own magnifying glass, how clever 🙂
Sally says
I love this. I just posted it on my blog (http://a-little-crafty.blogspot.com.au/2012/06/make-your-own-magnifying-galss.html) I think it's so neat. Thanks for sharing!
israel says
nice n cool
Casey Norris says
So would this magnify glass work to look at leaves and things??? I have a cub scout pack and this would be neat
Pradeep says
Very good
BLOBFISH says
doens't work because TUN TUN i put a paper do OHHHHHHHHHHHHHHHHHHHHH
desconosido says
mongolo noobs
Matias says
waaaaaw great !
Destiny says
Wow this is cool
Allison Trumbull says
I love love love this idea! I tried making a magnifying glass with the materials you recommended, and it works! This activity is safe and kid friendly, and I would highly recommend this as a craft project at schools across the world!