20th Century Invention - Mono Monday

This strange creature with one 'eye' missing is known as a cat's eye.

A cat's eye or road stud is a reflective safety device used in road marking.

This ingenious design originated in the UK in 1934 and is today used all over the world. The original form consisted of two pairs of reflectors set into a white rubber dome, mounted in a cast iron housing like this one.
A key feature of the cat's eye is the flexible rubber dome which is occasionally deformed by the passage of traffic. A fixed rubber wiper cleans the surface of the reflectors as they sink below the surface of the road (the base tends to hold water after a shower of rain, making this process even more efficient). The rubber dome is protected from impact damage by metal 'kerbs' – which also give tactile and audible feedback for wandering drivers. Brilliant!

They are something of a dying breed nowadays, and I had to go out on my bike and look for one. I found several which were in a sorry state, but this one still has one of its 'eyes', although it has clearly seen better days.

I did get some rather strange looks from passers by as I hurriedly photographed it in the middle of the road. The things that blippers do!