Monday, June 25, 2018

I noticed this thing about eyes that no one else knows

You can see the tear film on your own eyeball. If you look at a tiny spot of light, completely unfocus you eyes, the light will look like a circle. When you blink, you can see faint lines horizontally across the middle of the circle. These are the lines of thicker liquid blinking eyelids push together across the centre of your eye. You are actually seeing the water on the surface of your eye. There are other things to see too but these are more complicated to explain.

What you see looks a little like this
One way to try this is to put a straw hat over your face in the sun. See all the tiny spots of light coming through the straw. Don't loot at them, look beyond them - unfocus your eyes. Look at one unfocused. Now blink. You should see your tear film. Play around opening and closing your eye, focusing a little more and a little less.

You should also notice that the eye lashes are on the bottom of the circle of unfocused light you are looking at. The image is flipped. When you blink the eyelid comes up from the bottom.

What do you think? Is this genius or what?!

For the sake of the internet, I made this discovery when I was a child - looking at a spot of sunlight bouncing off the head of the bed at a relatives house. Today it is 25/06/2018 and I lay claim to this discovery.

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UPDATE (28/06/2018): I now think the "circle" you see when looking at light is a Bokeh effect of your iris. Still haven't worked out why it is upside down or what I can see.