The human eye – its parts and why it is an evolutionary marvel?

You've probably wondered how our eyes work. The eye is an organ that can be compared to a camera . Visual stimuli pass through the cornea and the lens, stimulate the visual cells located in the retina and form an image.

Do you see how interesting our eye machine is? Another example of its peculiarities is that people blink more when they are reading or concentrating on a task and less when they are relaxed or bored. Every time we blink it is because our vision is active, a complex moment of connection between our brain and our eyes.

Do you want to know more interesting facts about the human eye? Join us to discover why it is an evolutionary marvel. We also share with you important information for the health and maintenance of our eyes and the best models of glasses from Óptica Bassol to take care of them.

What is the human eye and what are its parts?

The eye is a very complex organ that allows us to see the world around us. When light enters the eye it passes through the cornea, iris, pupil and lens. The lens focuses the light onto the retina. Cells in the retina convert the light into electrical signals that are sent to the brain via the optic nerve. The brain interprets these signals and creates the images we see.

The human eye is made up of several parts, including the eyelids, cornea, iris, pupil, lens, vitreous humor, and retina. Let's look at the function of each of these parts of the eye:

The eyelids

These are two folds of skin that protect the eyes from light, dirt, and other foreign objects. They help keep the eyes lubricated and moist. They are made up of skin, muscle, and fat.

The skin of the eyelids is thin and delicate. The muscle of the eyelids is called the orbicularis oculi muscle. of the eyelids. This muscle is responsible for blinking. The fat in the eyelids helps keep the eyes lubricated and protected. The eyelids are very important for eye health, without them the eyes would be exposed.

The sclera

The sclera is the white, fibrous layer that covers most of the eyeball. It is located beneath the conjunctiva and above the choroid. It is responsible for protecting the eye from injury and maintaining its shape. It also helps blood flow in the eye.

It is made up of connective tissue, which is a type of tissue that is strong and resilient. It contains a large number of blood vessels that help provide nutrients and oxygen to the eye. It is not transparent, so it does not allow light to pass through. It is made up of three layers:

• Episclera: This is the outermost layer of the sclera. It is made of fine connective tissue and contains a large number of blood vessels.
• Scleral stroma: This is the middle layer of the sclera. It is made up of thicker connective tissue and contains a large amount of collagen fibers.
• Lamina fusca: This is the innermost layer of the sclera. It is made up of denser connective tissue and contains a large number of blood vessels.

The cornea

The cornea is the clear layer that covers the eye. It is located at the front of the eye and helps focus light. The cornea is made of connective tissue and has no blood vessels.

The crystalline

The crystalline lens is a kind of clear lens that is located behind the cornea. The lens helps focus light on the retina . It can change its shape to focus light on objects both near and far.

The iris

The iris is the colored part of the eye. It is located behind the cornea and in front of the lens. It controls the amount of light that enters the eye. It has a muscle that contracts and dilates to open and close the pupil.

The pupil

The pupil is the black hole in the center of the iris. It opens and closes to control the amount of light entering the eye. When there is a lot of light, it closes to let in less light. When there is little light, it opens to let in more light.

The retina

The retina is a light-sensitive layer of tissue at the back of the eye. It contains photoreceptor cells that convert light into electrical signals. These electrical signals are sent to the brain through the optic nerve.

The retina contains cells called rods and cones:

• Rods are responsible for peripheral vision and night vision.
• Cones are responsible for central vision and color vision.

The optic nerve

The optic nerve is a cable that connects the eye to the brain . The optic nerve sends electrical signals from the retina to the brain. The brain interprets these electrical signals and allows us to see.

Aqueous humor

Aqueous humor is a fluid found between the cornea and the lens (anterior chamber). It helps maintain the shape of the eye and nourish the cells of the lens and part of the cornea.

The vitreous humor

The vitreous humor is a gel found at the back of the eye. It helps maintain the shape of the eye and protect the retina.

How does the human eye work?

The human eye works thanks to the brain-eye connection. Without it, we would not be able to see. It is one of the most complex and fascinating connections in the human body. When light enters the eye, it is focused by the cornea and lens and projected onto the retina.