After trekking up a mountain, there's a particular feeling you get when you finally stand at the top and take in the view. It’s the same feeling when you see the ocean spreading out beyond the horizon, or when lying back on a clear night to see the endless stars shining down. You can't help but stop and stare at the earth, sea and sky and their phenomenal beauty.

Have you ever spent time looking high and low for something that you just can't find – your keys, your phone, a bag, a book – only to have somebody else point to it straightaway, right there in plain view? It can be so frustrating!

It's well established in biological science that not everything a person 'sees' at any given moment is really there. Where the optic nerve connects to the retina at the back of each eye is a spot with no photoreceptors.  Every image that our brain receives from our eyes has a 'blind spot'. Remarkably, our brain fills the hole so what we 'see' is a combination of what our eyes report and what our brain believes to be there.