Eye components .. What is an eye made of?

The human eye is an incredible and complex organ, made up of several components that work together to allow us to see.

In this blog post, we’ll explain the anatomy of the eye and discuss the different components that make up this amazing organ.

Eye components what is an eye made of


A person can recognize his surroundings through his five senses, namely: hearing, smelling, taste, touching, and finally the sense of sight, and the eye acting like a digital camera is represented by many qualities, including the following: [1]

  • Light is mainly focused on the cornea of the eye, which is represented by the camera lens.
  • The iris controls the amount of light reaching the back of the eye by automatically changing the size of the pupil, which represents the diaphragm in the camera.
  • The concentration of light on nearby objects is automatically increased by a process called accommodation eye, via the crystalline lens located just behind the pupil, which is similar to the autofocus lens inside the camera.
  • Concentrated light by the cornea and the crystalline lens reaches the retina, which is similar to the image sensor inside the camera, so the retina converts light into electronic signals, and then transmits it to the optic nerve to the visual cortex.

The human eye is similar to a ball, with a slight emission in its front, and the eye consists of three basic layers located on top of each other; which in turn form the eyeball, and divide the eye from the inside into three main chambers, and the following is an explanation of all these components:[2]

What is an eye made of? Eye components and their functions

  • Eye layers, the basic layers of the eye can be summarized as follows:
    • The sclera: Sclera is the white part of the eye, and forms a wall to support the eyeball. This layer thickens at the area around the optic nerve. This layer is covered by the conjunctiva. It is a mucous membrane that helps moisturize the eye. The sclera layer extends to connect to the cornea.[3] The corn 4]
    • ChoroidThe chorionic layer is located between both the retina and hard layers. This layer is thicker in the back of the eye; it is 0.2 mm, and its thickness begins to decrease gradually in the eye contour to reach 0.1 mm. This layer contains blood vessels in the eye, in addition to containing the epithelial pigment tissue of the retina. The retina provides oxygen and food necessary for the outer layer of the retina. This layer contains melanin pigment, which absorbs light and reduces its reflection inside the eye; because of the negative impact on the vision process. This pigment protects the blood vessels in the placenta layer. From the effect of negative light in it, the placenta forms the uveal tract, which in turn includes both the iris and the ciliary body, and can be detailed as follows:[5]
    • Iris: Iris is the colored part of the eye, which regulates the amount of light waves pass to the eye, and the iris in the middle of it contains an opening known as pupil, which passes light organized by the iris. 6]
    • Ciliary body: Ciliary bodies expand or contract, helping the lens of the eye to change shape and get more accurate focus.[ 6]
    • The retina: It is the third and last layer of the eye layers of the eye. It is worth mentioning that the retina contains millions of light-sensitive cells, and these cells are within two main forms: conical or bacillus. The bacillus cells sense monochromatic colors during dim light, while cone cells are concentrated within an area called Fovea centralis; which helps to see at a high and sharp concentration. When light comes into contact with these sensitive cells, they are converted into electrical signals transmitted to the brain by the optic nerve. [7]
  • Eye rooms: The chambers are divided into three sections, namely: [2]
    • The anterior chamber of eyeball is the front of the eye, located between the cornea and the iris.
    • The posterior chamber of eyeball is located between the iris and the lens.
    • The vitreous chamber is located between the lens and the back of the eye.
  • Eye-protective components: There are several other parts of the eye whose function is to protect the eye, including:[8]
    • Bone cavity of the eye: The eye is protected by having a cavity that allows it to move freely despite the presence of blood vessels, nerves, and muscles in the eye.
    • Eyelashes: They are short and strong hair that grows on the edges of the eyelid, and is considered as an eye barrier; as it prevents insects and foreign objects from entering the eye.
    • Eyelids: They are thin sheets of skin and muscles located above and below the eye, protecting the eye from insects and foreign bodies, or when heavy light is highlighted on the eye, where they close spontaneously and very quickly for protection.
    • conjunctiva: It is located on the back surface of the eyelid and covers the front surface of the eye down to the edge of the cornea, and works to protect the tissue underneath.
    • Tears: It is salt water that constantly floods the surface of the eye to maintain its moisture, transports oxygen and food to the cornea, and tears contain antibodies that reduce infection.

Age-related eye problems

As a person ages, he is more likely to develop age-related eye diseases, including the following:[9]

  • Macular degenerationIt is an age-related disease that leads to poor vision concentration of objects, while performing tasks such as reading and driving a car.
  • CataractAlso Called Cataract, It Means A Blackout In The Lens Of The Eye, Which Causes A Glow In Vision, And Thus Blurrear In Vision.
  • Diabetic Eye Disease: It is a complication of diabetes, and one of the main causes of blindness, and this occurs when blood vessels inside the retina are damaged by diabetes.
  • Glaucoma, a group of diseases associated with high intraocular pressure, may damage the optic nerve, affecting lateral vision and can cause vision loss.
  • Dry eyes: Dry eyes occur when the ability of the eye to produce tears naturally occurs, as this makes it difficult to perform some daily activities, such as reading or using a computer for long periods.


  1. Liz Segre and Stephen Bagi, “Eye anatomy: A closer look at the parts of the eye”, www.allaboutvision.com, Retrieved 14-5-2019. Edited.
  2. “Eye Anatomy and Function”, www.uofmhealth.org,17-7-2018, Retrieved 14-5-2019. Edited.
  3. “Sclera”, www.healthline.com,9-2-2015, Retrieved 14-5-2019. Edited.
  4. “How Does The Human Eye Work?”www.nkcf.org, Retrieved 14-5-2019. Edited.
  5. Troy Bedinghaus, OD (1-6-2017), “What is the Choroid in Eye Anatomy?”www.verywellhealth.com, Retrieved 15-5-2019. Edited.
  6. “How your eye works”, lookafteryoureyes.org, Retrieved 15-5-2019. Edited.
  7. Ker Than (5-5-2016), “How the Human Eye Works”, www.livescience.com, Retrieved 15-5-2019. Edited.
  8. James Garrity (1-3-2019), “Protective Features of the Eyes”, www.msdmanuals.com, Retrieved 15-5-2019. Edited.
  9. “Age-Related Eye Diseases”, nei.nih.gov, Retrieved 15-5-2019. Edited.

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