Arts & Crafts

How to Build a Water Microscope

By: Lisa Glover
A disposable cup turned into a magnifier.
minute activity
For All Ages
Critical Thinking

Work with your child to build this water microscope from The Highlights Book of Things to Do. Together, discuss how looking at the objects under a microscope is different from looking with the naked eye.

You don’t need a big contraption to view objects under a microscope. You can make a simple microscope at home.

What You'll Need

What to Do

  1. Carefully cut the cover off the googly eye. Take it apart. Have an adult help with anything sharp.

  2. Trace the plastic eye cover onto the bottom of the cup. Then draw an upside-down U on each side of the cup. Cut along all the lines you’ve made, so the cup has a hole in the bottom and two open sides.

  3. Cut four thin, small pieces of tape. Tape just the edges of the eye cover to the inside of the cup so the curve goes inside.

  4. Spoon a little water into the eye cover so it forms a pool. Now you can put small objects under it and see them magnified. You may have to move the cup a bit to get the right spot.

Why It Works:

The pool of water on the googly eye creates a convex lens. Convex lenses are thicker in the middle and thinner around the edges. They bend the light passing through them, making the object underneath appear larger.

From The Highlights Book of Things to Do

Author Photo
By: Lisa Glover