Gather a cardboard tube, three small mirrors, clear plastic, colored beads or sequins, tape, scissors, and decorative paper
Cut the mirrors to fit the tube length
Tape the three mirrors together into a triangular prism with reflective sides facing inward
Insert the mirror prism into the cardboard tube
Cut a circle of clear plastic to fit one end of the tube
Place colored beads or sequins on top of the plastic
Cover the beads with a second clear plastic circle and tape it in place
Add a small cardboard ring or cap to hold the bead chamber securely
Cover the other end of the tube with decorative paper or leave it open as an eyepiece
Look through the open end and rotate the tube to see changing patterns