Have you ever noticed how a cat’s eyes seem to shine and glow when car headlights hit them?
Road “cat’s eyes” (the little reflective studs) typically seen in the centre of a road between lanes work using a clever optical trick called retroreflection.
How do they work?:
- Inside each cat’s eye are tiny glass beads that act as prisms
- When car headlights hit them, the light enters the prisms,
- The light then “bounces” around inside
- And it then gets sent straight back towards the driver
So even in the dark or rain, they appear to be both bright and clear.
A couple of extra cool facts:
- Many have a rubber housing that flexes when a car drives over it, which actually wipes dirt off the lens (self-cleaning!)
- Different colors are used to mean different things:
- White: lane markings
- Red: edge of the road
- Amber: central reservation
- Green: slip roads or junctions
Fun fact: they’re called cat’s eyes because the inventor thought they looked like—yep—a cat’s eyes glowing at night 🐈✨
