There’s a lot of beauty in the ordinary things. Isn’t that the point?
After reading an incredible book by Jackie Higgins: Sentient, I have found myself delving deeper into what that means for us in our daily lives, and while out on game drive my mind often wanders to how that translates to the animals around us. In my previous blog, I spoke about what it means to be sentient, and how senses and sentient beings are inextricably linked. As humans, we can observe how familiarity dulls our senses. So let’s look at arguably our most vital, and complex sense: Sight.
Ranger Kate Arthur explains the structural adaptations of eyes in nature in her blog – Structural Adaptations: Eyes. While keeping it simple, sight starts when photos of light or little packets of energy so small, bounce off an object and enter the pupil of our eye, travel through to the back of the eyeball and reach the photoreceptors of the retina. Here they hit an opsin. This sets off a cascade of chemical reactions that ends in an electrical spark. This spark becomes a signal that shoots down nerves to the brain and the external world becomes something we can perceive internally.
We are all guilty of underappreciating – and underestimating – our sensory powers.
Scientists still have little idea how nerve cells can give rise to the inner experience: how the tangible becomes intangible. Yet, this astonishing transformation plays out with the mundane, microsecond repetition.
The calculus of colour perception across the animal kingdom is relatively straightforward; species see different rainbows of colour depending on how many colour receptors they have. Monochromats with just one type of cone – seals and wales for example – are colour-blind and see the world in one hundred shades of grey.
Dichromats with two – a list that contains nearly all mammals from Aardvarks to Zebra – see a reduced rainbow. Take a Leopard for example, the two colour-detecting cones let them see blue-violet and yellow-green wavelengths but not red-orange. Meaning they mainly see things in shades of yellow, grey, and blue tinges (but some researchers think that cats may also notice some shades of green). If you’ve ever wondered How Leopards See the World, read Robyn Morrison’s amazing blog about it.
Then there are the rare mammalian trichromats, us. Kept only company with baboons and great apes, our sight is far from ordinary. Most vision experts agree that the average and unremarkable human eye can probably see as many as several million shades of colour.
I also want to divert briefly and mention that I’ve only really spoken about colour vision here, not the so-called strength of vision. Take birds of prey for example. They have excellent long-distance vision, but eagles and vultures stand out. They can see clearly about eight times as far as humans can, meaning roughly, a vulture can see an 8cm object on the ground from 1km up in the sky!
Our human brains compensate for our eyes’ shortcomings, allowing us to perceive more colour in the world than our mammalian counterparts. But, take a moment. Look up from this screen and open your eyes to your surroundings. Let the beauty of the world around you of the incredible gift of sight.