If you think animals see the world like we see, then its not true because different animals see the world differently. Animals like dogs and cats are living without full range of colour spectrum perception. Even bull fighting bulls can’t see the red colour. Red colour really don’t make bulls angry, they are colour-blind to red. Its the natural state of these animals for colour perception. Dogs, cats and other such animals see the world differently than us and not able to distinguish between different colours.
Unlike humans animals like dogs, cats, rabbits have different colour vision than humans and see the world in shades of blues and yellows. About a decade ago scientists did a test on cat’s colour vision by putting one coloured jar and one grey jar in front of a cat. If cat touched the coloured jar they offered cat a fish and if it touched the grey one then nothing was offered to cat. And after about 100,000 tries they concluded about 50/50 results and thought that cats can’t see the colours.
What actually causes different living beings have different vision is the cone and rod cells in retina of eyes. Cones are responsible for colour vision while rods helps view in dim lights. Humans normally have three types of cone cells let them view a wide range of colours while animals like dogs and cats have two types of cone cells make then colour-blind to most of the colour ranges. Whereas, some animals have more than three types of cones make them able to view more colours that humans can’t see.
Each of three cones have their own range of wavelengths and defined by L, M and S cone.
L cone is response to orange/red colours and long wavelengths
M cone is response to green/yellow colours and medium wavelengths
S cone is response to blue/purple colours and short wavelengths
If some of the animals are colour-blind, there’re animals which can see the colours which we humans can’t see. Ability to see in more colour wavelengths make diving birds to see and catch prey and food underwater and let bees to see deep inside flowers that humans can’t see with naked eye. Some species like goldfish, guppy, primate fish and other such mammals have three types of cones and have more vibrant vision than other animals and species.
Bulls are completely blind to colours and have only grey vision, then why bull charge the red cape in bullfighting? Well its not because of red colour of cape but because of the movement of the cape that irritate the bull, and that’s why bulls charge the cape in bullfighting.
Horse vision is somewhat like grey with different shades of black and white but slightly parted view because eyes pointed to sideways unlike straight vision of humans and has black spot in between two eyes visions.
Snakes are capable of viewing more wavelengths than humans and have day and night vision to catch prey independent of sun-light. Humans normally have short, medium and long wavelength range whereas snakes take it to microwaves which let them sense the prey with heat and their night vision is similar to thermal imaging.
Most animals not even have a single cone in their eyes and they are completely colour-blind. Colour-blind doesn’t mean someone can’t see, but see in different colours or in grey spectrum and that’s all because of the lack of one or two types of cones in the eyes. Because, cone cells define the wavelength of someone’s vision.
Photo credit: yukariryu