Eyes

 

I have decided to do a few posts about our bodies, starting our eyes, why well I have a book belonging to Sam about our eyes. I think there will be a number of posts concerning our eyes, staring with this introduction.

Our eyes are the most tool we have for collecting information about the world around us. Without our sense of sight things can become much more difficult.

The bony hollow in which the eye sits is the socket or orbit, above they eye are our eyebrows which help to prevent dust and dirt getting into the eye. Our eyelashes do the same thing, and we produce tears to keep the eyes moist and clean.

The white part of the eye is the sclera, and the coloured ring is the iris, in the centre is the pupil which looks like a solid black dot.

However, the pupil is a hole and covered by a transparent layer known at the cornea. Light enters through the pupil.

The eye is held in place by delicate muscles and ligaments, which allow our eyes to move. The muscles of the two eyes usually work together, so our eyes move together.

Inside the eye there are two large spaces, called chambers, the front one is filled with a watery liquid called the aqueous humour.

Between the two chambers is a small disc of jelly called the lens, this bends the light as it enters the eye. The larger chamber behind the lens is filled with a soft jelly, called vitreous humour.

The curved inner surface of the eyeball is lined with a sensitive layer called the retina, which is linked to the optic nerve which sends signals to the brain.