The human eye is one of nature's most complex and advanced structures outside the brain itself. It has been estimated that one half of the brain's power is devoted to processing vision, which makes sense considering how important vision is to daily life. Most importantly, people's eyes are working constantly to process close to 36,000 bits of information every hour. One human eye alone contains nearly 12 million photoreceptors which are responsible for interpreting and converting light into signals that give our brain the power to process vision, making the eye clearly a marvel of the natural world.
How Vision Works
While eyes are incredibly complex, the very basic mechanics of the eye can be understood by all. Your eyes are essentially a biological camera, which specialize in focusing light onto the photo-receptor cells in the back of the eye (also known as the Retina).
The visible part of the eye is mostly responsible for regulating the how much light enters into your eye, which is important since the retina cells located in the back of the eye (rods and cones) are extremely sensitive. Once light reaches your retina, the photoreceptor cells alter their shape via light sensitive proteins located within their cell membrane. When these photoreceptor cells change their shape, nerve impulses get sent to the brain, allowing the brain to interpret these signals to decipher colors, light, and process the signals as vision.
Anatomy of the Eye
Each and every part of your eye serves an important purpose in the vision process. Learn the role of each part of your eye by viewing the image to the right, and reading about the role of each part below.
With how complex your eyes are, it's important to protect them properly. Make sure you have the proper accessories and solutions when using any eye care product. Remember AC Lens has a full stock of eye-care products for all optical health needs.
For more information about eye care terms, visit our vision glossary.
- Cornea: Clear cover over the Iris and Pupil, which allows light into the eyes.
- Pupil: The black dot in the center of the eye, which filters how much light is allowed to enter the eye
- Anterior Chamber: Chamber that sits between the iris and cornea, which holds liquid nourishment for the cornea and pupil.
- Iris: This is the colored part of the eye surrounding the pupil. The iris serves as a diaphragm to adjust the pupil's size.
- Hyeloid Canal: The hyeloid Canal is a narrow duct that can quickly move liquid through the eye.
- Sclera: The outer layer of the eyeball that appears white in coloration. The sclera gives the eye shape and strength.
- Lens: Sits behind the cornea, iris, and pupil, and focuses light onto the retina in the inner-part of the eye.
- Conjunctiva: Mucous membrane that surrounds the exposed part of the eye and eyelid to protect it from contaminants.
- Choroid: Thin layer of blood vessels located at the back of the eye to provide nourishment for the entire eye.
- Retina: Membrane made of photoreceptor cells in the back of the eye. Converts light into signals read by the brain.
- Rods: Photoreceptor cells found in the retina that are sensitive to non-colored light. Rods are better for night vision.
- Cones: Photoreceptor cells found in the retina that are sensitive to detail and color. Cones are used mostly for day-time vision.
- Macula: The macula is the center of the retina, and is primarily made of cones for detailed and acute vision.
- Fovea: The Fovea is a depression in the retina where no rods are located. The Fovea assists in providing acute vision.
- Vitreous Body: This is the "center" part of your eye, containing a clear gel-like substance.
- Optic Nerve Head: This is where the optic nerve connects to the eye. No photoreceptors are located on this spot..
- Ciliary Body: Sits next to the lens, and is responsible for focusing and providing nutrients to the the lens.
- Optic Nerve: The optical nerve is responsible for sending signals from the retina to the brain for interpretation.
- Optical Muscles: Responsible for eye movement and focusing the eyeball on objects within viewing range.
- Eyelid: Protects the eye from harm,and rewets the eye by spreading tears upon blinking.
- Eyelashes: Help to protect the eye from particles from contaminants and particles that would otherwise enter the eye.