Animals and colour vision
What other animals see is very unlike our view of the world.
500 million years ago trilobites, small sea animals, had compound eyes.
These are primitive imaging devices. They are a collection of light
detectors, each with a simple lens, and packed together like a honeycomb.
Most living things are sensitive to light. Plants use light energy
for growth. Flowers turn to follow the sun but they do not see.
Some animals use light to find food and avoid becoming food.
The light-detecting devices (eyes) of living creatures differ considerably,
as do the nervous systems to which their eyes are linked.
