The human eye is much like a digital camera. Light is focused by the cornea (the clear front surface of the eye) which acts like a camera lens. The iris controls the amount of light that reaches the back of the eye by adjusting the size of the pupil (when there is very little light, the pupil dilates to allow more light to reach the back of the eye) The crystalline lens is located directly behind the pupil. This further focuses the light through a process called accomodation, helping the lens automatically focus on near and approaching objects, much like the autofocus on a camera lens. The light that has been focused by the cornea and the crystalline lens then reaches the retina (the light sensitive inner lining of the back of the eye), which acts like the electronic imaging sensor of a digital camera. The optical images are then converted into electronic signals and are then transmitted via the optic nerve to the are of the brain that controls our sense of sight (the visual cortex)
Anatomy of the Eye
Cornea: This is the clear front window of the eye, which aids in transmitting and focusing light into the eye.
Iris: This is the coloured part of the eye, and by dilating and contracting the pupil, it regulates the amount of light that enters the eye
Lens: The transparent structure inside of the eye that focuses light rays onto the retina.
Macula: The macula allows us to see fine detail clearly – it is a small area in the retina that contains light sensitive cells.
Optic Nerve: This is the nerve that connects the eye to the brain, carrying the impulses created by the retina to the brain to be processed so they can be interpreted as images.
Pupil: This is the dark centre of the iris. It’s size is altered by the iris to adapt to the brightness or darkness of your surroundings
Retina: The layer of nerves that line the back of the eye. The retina senses light and creates impulses that are sent along the optic nerve to the brain
Vitreous: The clear substance, much like jelly, that fills the middle of the eye.