This classic "Eyes That Follow" optical illusion creates the effect that eyes are watching your every move.
This easy tutorial can be quickly assembled in 45 minutes. This is also easily adaptable. For example, add a set of "following eyes" to a pumpkin to create a creepy jack-o-lantern, or use a glow stick as a quick-to-setup light source.
Materials Pingpong ball (1 or 2) Cardboard Box Pencil X-Acto knife or Scissors Cutting Board Hole Puncher Single-Sided Tape Double-Sided Tape NeoPixel Strip (length of 10 LEDs) Adafruit Gemma 3 x AAA Battery Pack AAA x 3 Alligator Clip Test Leads x 3 Computer USB Cable - A / MiniB Black Sharpie Marker Multimeter for Debugging Gemma and LED strip (in case you need to debug the electronics)