Code red

HAVE YOU EVER wondered why traffic lights, brake lights and warning signs are all red? The retina of our eyes has two types of light-sensitive cells called rods and cones, found in a layer at the back the eye which processes images. These cones are receivers for tiny visible light waves. The sun is a natural source for visible light waves and our eyes see the reflection of this sunlight off the objects all around us. The colour of an object that we see is the colour of light reflected, while all other colours are absorbed. Car headlights are another source of visible light waves.

Why red is so effective

Red has the longest wavelength of all colours in the visible spectrum. Its long wavelength results in red colours being scattered the least. Due to the receptors for red colours in the eye being clustered in the area near the centre, where the sharpest images are formed, it is easily visible over long distances, even in