It’s always a bit of a shock when you take a pic that makes the hairiest human in your home look…well, a little possessed.
But there’s a fascinating reason why it happens...
And it explains a lot!
Well it turns out that almost all our pets’ eyes have something ours don’t. And it basically gives them a superpower that only becomes obvious in photos.
So what is that glow coming from their eyes?
Well, it’s actually a highly reflective membrane (like a mirror) called the ‘tapetum’ that sits in the back of their eyes over their retina. So once light comes into their eyes, it doesn’t ‘just’ get absorbed by their retina. It actually bounces back off the tapetum and gives the retina a second chance at seeing it. So it’s basically a light boost on a dark night. Meaning that every animal with a tapetum (lots of nocturnal animals have them) can see in the dark. It's quite the superpower!
In fact, it’s thought that having that tapetum can boost a cat’s night vision by 44%. And a dog by around 40%. Handy! And explains why they can find their way into and out of your bedroom at night without bumping into anything. Unlike us…
Interestingly, the tapetum also comes in different colours. For puppies and kittens, it’s normally blue or grey. While in adult dogs and cats it’s yellow, green or orange.
And while cats rely on Vitamin B2 crystals to fuel their tapetum's mirror, dogs use Zinc crystals.
Oh and in case you're wondering, if you don’t want that tapetum to make your otherwise placid friend look like a poltergeist in pictures, just try turning your flash off. You’re essentially seeing yourself (and your flash) when you look in their eyes!
If you’re wondering what our red eyes are in photos, that’s just the camera flash illuminating all the blood vessels in our retina. Without the reflective, coloured mirror to add some extra interest to pictures.