I was like ooooh, it's them cones again!
There is nothing I like doing more than to sit outside in the sun. Don’t get me wrong, you must stay protected in the sun; however, some of us have certain privileges. Did someone say melanin? My highly melanated skin thrives from the vitamin D kisses the sun brings. Especially when you live in Manchester, were rain is near enough our second language. I love nothing more than to bask in the sun with my eyes closed, just so I can take note of the sensations around me. Have you ever noticed that when you close your eyes in a well-lit room you can see the red of your eyelids? Your eyelids form a translucent barrier which still allows for the light to stimulate the photoreceptors of your retina.
Okay, let's take a couple of steps back. I realise that this may have gone over your head. Let me give you some context. Let's talk through the journey of light. Your retina is full of receptors and cells, which are sensitive to light. You have receptors which are sensitive to monochromatic vision (black and white e.g. at night), and colour vision (during the day). The receptors which process colour vision are more concentrated in an area of the retina called the fovea. This is where the lens aims to focus the light onto. Humans usually gave 3 types of cones; red, green, blue. All of which are stimulated at specific wavelengths of light. All the colours you can see are made up a combination of these cones firing in a coded manner.
I was sat outside in the sun the other day and my face was towards the sky as my eyes were closed. I opened my eyes again and everything had a blue tinge to it.
"I was like ooooh, it's them cones again!"
Let me explain. When I closed my eyes in those light conditions, my red cone cells were stimulated continuously, and they essentially got a bit tired. Once I opened my eyes again, my cone cells were still receiving the red, blue and green light, but only the blue cones were active and ready to fire. It takes some time for the red cones to adjust themselves and get back to normal again, hence the blue tinge to everything.
If being in the sun is not your thing, then here is a cool experiment you can try from the comfort of your own screen, which follows the same principles as what I described above. Stare at this inverted American flag without moving your eyes for about 20 seconds, then look away. You'll briefly see an afterimage of the normal flag. If your blue receptors get tired out by staring at a blue image, the afterimage will be the inverted colour: orange. If you exhaust your red receptors, the afterimage will be green/blue.
See how amazing your eyes are! (no pun intended). I am so lucky to have my eyes, they allow me to see colour and shape, the things I appreciate about creation. And to think, these little receptors allow me to make sense of the world that I live in. Life may be a little gloomy and hopeless right now on lockdown, but remember you have little miracles happening in your body every time you do something as simple as double-tapping a photo on Instagram. So the next time you're outside basking in the sun remember that your cones are at work even when you are not.