Eye Anatomy-How the Parts of the Eye Work

The human eye is a highly specialized organ. The eye has the ability to receive visual images, which are then transmitted to the brain. How the eye works is fascinating. After the brain, the eye is the next most complex organ in the body.

1.The Cornea is the clear “window” found at the front of the eye. The cornea is made of a tough, transparent tissue. This tissue keeps dirt, germs, and other particles from getting into the eye. Some of the sun’s damaging ultraviolet (UV) light is prevented from entering the eye by the cornea.
2.The pupil is the black dot at the center of the eye. It is an opening at the center of the iris through which light passes.
3.The Macula is a small but critical area in the center of the retina. The macula manages translating light into images needed to clearly see the details of objects in central vision.
4.The Iris is the colored part of the eye. The primary job of the iris is to regulate the amount of light that reaches the retina. It does this by controlling the size of the eye’s “window,” or the pupil.
5.The lens of the eye (or crystalline lens). This transparent structure is on the inside of your eye. It is a natural lens found behind the iris. The lens changes its thickness and curvature, allowing the eye to adjust focus on objects from varying distances. If the natural lenses in the eye are irregularly shaped, your eye doctor may prescribe glasses or contact lenses to correct vision.
6.The Optic Nerve is a bundle of about 1.2 million nerve fibers that send visual information to the central nervous system (brain).
7.The Retina is a key connection between the light that enters your eyes and the images you see. Special cells called photoreceptor cells in your retina react to light and pass signals to your brain that let you see what is around you.
8.The Sclera is most times known as the “whites” of the eye, covering more than 80% of the eyeball’s surface. It has grooves that help properly attach the eye to the tendons to supply stability and protection while staying flexible. This allows the eye to move and track objects as needed.
9.The Optic Disc is where the nerve fibers of retinal ganglion cells join and mark where the optic nerve begins. The optic disc also serves as the starting point for major blood vessels that feed the retina.

Path the light takes to create an image:
Step 1: Light enters the eye through the cornea.
Step 2: The light passes through the pupil, which is the opening in the center of the iris. The pupil adjusts in response to the intensity of the light by getting larger or smaller.
Step 3: The lens focuses the light onto the retina by adjusting its shape to bend and refocus the light a second time, ensuring the clearest image of what you are looking at.
Step 4: The light is then projected onto the retina Once the light is focused on the retina, the light-sensitive layer of tissue at the back of the eye. The retina converts the light into electrical signals. The nerves in the retina collect all the electrical impulses.
Step 5: The optic nerve transmits visual information to the brain through the optic nerve at the very back of the eye up to the occipital lobe in the back of the brain. The brain then interprets these signals as an image.

This is just a condensed version of how the eye works. There are more micro components within the eye to aid the major parts of the eye listed above.

Watch this video from The American Academy of Ophthalmology https://youtu.be/Sqr6LKIR2b8




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