The Eye
How do your eyes work?
Everything your eyes do starts with light from the outside world. Your eye structure lets light enter and pass through a series of clear components and sections, including the cornea. Aqueous humor, lens and vitreous humor. Those structures blend and focus light, adjusting how far the light beams travel before they come into focus.
The focus needs to be precise. If it isn’t, what you’re looking at appears blurry. Your eye has muscles that can make subtle changes to the shape of your eye, moving the focus point so it lands correctly on the retina.
When light lands on the cells of your retina, those calls send signals to your brain. The signals are like coded messages describing everything they can about the light. That includes the colour, how intense it is and any other relevant details. Your brain decodes and processes the signals and uses them to ‘build’ the image you see.
Anatomy
How do eyes work?
Human eyes are complex, and it takes many parts working together correctly for you to see.
Eye anatomy
The parts of your eye include -
- Cornea – This protects the inside of your eye like a windshield. Your tear fluid lubricates the corneas. The corneas also do part of the work bending light as it enters your eyes.
- Sclera – This is the white part of your eye that forms the general shape and structure of your eyeball.
- Conjunctiva – This clear, thin layer covers the sclera and lines the inside of your eyelids.
- Aqueous humor – This is fluid that fills a space called the anterior chamber. The pressure of the aqueous humor helps maintain your eye’s shape.
- Iris – This part contains the muscle that controls the size of your pupil. It’s also responsible for eye colour. The iris can be brown, blue, green or hazel (a blend of brown, yellow and green).
- Pupil – This is the black circle inside the iris. It’s like an adjustable window to the inside of your eye. It widens and narrows to control how much light enters your eye.
- Lens – This focuses light that enters your eye and directs it to the back of your eye.
- Vitreous humor – This clear, gel-like fluid fills the space between the lens and retina. It helps your eye hold its shape. It’s also sometimes known simply as ‘the Vitreous’.
- Retina – This thin layer of light-sensitive cells at the back of your eyes converts light into electrical signals. It contains rods (which help you see in low light) and cones (which help you see colours).
- Macula – This small area of your retina is key to your vision. It’s responsible for the centre of your visual field. It also helps you see colour and fine details.
- Optic nerves – This connects your retinas to your brain. It’s like the data cable that carries signals from your eyes, with connection points linking to multiple brain areas.
- External muscles – These control your eye’s position, alignment and movement. They also contribute to your eye’s shape, which is part of your ability to switch your vision’s focus between near and far objects.
