Every sentient creature has receptors that capture a certain kind and range of stimuli from the external environment. Other animals have senses we do not share: for example, bats and dolphins use sonar for navigation, and homing pigeons and salmon have deposits of magnetite in their bodies that enable them to detect the Earth’s magnetic field to find their way home. Even the senses that we do share with other animals, we posses to different degrees: we don’t smell as keenly as wolves, or see as well as eagles. Senses have a limited range of sensitivity, and capture only certain kinds of data in their net.

Knowing how other animals gain sensory information makes us aware of our own specifically human perception of the world, a world that most people assume to exist outside themselves. We are not perceiving the world as it is, we are sensing in a human way, and building our knowledge from a limited range of all sensory possibilities.

Artist and researcher Nickolay Lamm created this fascinating series that compares the differences between how humans and cats see the world. Each comparison includes one scene appearing in two different ways. The top image shows a panorama of crisp and colorful human vision while the bottom image shows a much more washed out, blurry cat perspective.

Fascinating Comparison Shows How Cats See the World

To create the project, Lamm conducted an extensive amount of research, collaborating with doctors from All Animal Eye Clinic in Michigan, The Animal Eye Institute, and The Ophthalmology Group at the University of Pennsylvania Veterinarian school to ensure that he presented an accurate depiction of our little feline friends.

Lamm discovered a variety of interesting facts, learning that cats can see 6-8 times better than humans in dim light and at night, they have a larger visual field of 200 degrees (compared to 180 degrees for humans), and a cat's visual acuity is between only 20/100 to 20/200 compared to a perfect vision acuity of 20/20. Although a cat is really unable to appreciate a wide, distant cityscape, the project vividly illustrates how humans and cats have vision that is clearly constructed for function and survival.

Cats were originally thought to be dichromats (like dogs and protanopic humans But, there is some research out there that suggests cats may also have a third cone type that indicates cats might see the world similar to us, humans. But cats might just see blues and yellows (red-green color blind), so cats are probably like that, but with some green thrown in from that third cone type.

Our retinas have many more cones than cats, this gives us fantastic day vision with lots of vibrant colors and excellent, detailed resolution. Dogs and cats have many more rods, which enhances their ability to see in dim light and during the night.

The increase in rods also enhances their “refresh rate”, so that they can pick up movements much faster (very helpful when dealing with small animals that change direction very quickly during a chase). These differences also help them to have great night vision, an excellent ability to pick up and follow quick movements, but at the cost of less vibrant color, with less detailed resolution. Interestingly, this also means that humans have the ability to see very slowly moving objects at speeds 10 times slower than cats (that is to say that we can see very slow things move that would not appear to be moving to a cat).

We cannot say that colours, sounds and tastes exist out there independent of our experience of them. So we may begin to wonder whether anything can be said to exist independent of our experience of it.

Make a distinction between two senses of the word ‘sound’. Sound1 is physical sound – the vibrations in the air that that are caused by the falling tree. Sound2 is experienced sound – the actual wallop that we hear when the tree hits the ground. If a tree falls in a forest and there is no one thee to hear it, there is sound1 but no sound2.

The three problems before may confirm your suspicion that philosophers spend their time asking useless questions that have no practical value. Surely life is too short to worry about what the world does when we are not watching. Perhaps all that really matters is that the world is there as it is supposed to be when we are near. What objects do in their free time is no concern of ours.