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Home » Your Eye Health » How the Eye Works

How the Eye Works

To understand how the human eye works, first imagine a photographic camera—since cameras were developed very much with the human eye in mind.

How do we see what we see?

eye diagramLight reflects off of objects and enters the eyeball through a transparent layer of tissue at the front of the eye called the cornea. The cornea accepts widely divergent light rays and bends them through the pupil—the dark opening in the center of the colored portion of the eye.

The pupil appears to expand or contract automatically based on the intensity of the light entering the eye. In truth, this action is controlled by the iris—a ring of muscles within the colored portion of the eye that adjusts the pupil opening based on the intensity of light. (So when a pupil appears to expand or contract, it is actually the iris doing its job.)

The adjusted light passes through the lens of the eye. Located behind the pupil, the lens automatically adjusts the path of the light and brings it into sharp focus onto the receiving area at back of the eye—the retina.

An amazing membrane full of photoreceptors (a.k.a. the “rods and cones”), the retina converts the light rays into electrical impulses. These then travel through the optic nerve at the back of the eye to the brain, where an image is finally perceived.

A delicate system, subject to flaws.

It’s easy to see that a slight alteration in any aspect of how the human eye works—the shape of the eyeball, the cornea’s health, lens shape and curvature, retina problems—can cause the eye to produce fuzzy or blurred vision. That is why many people need vision correction. Eyeglasses and contact lenses help the light focus images correctly on the retina and allow people to see clearly.

In effect, a lens is put in front of the eye to make up for any deficiencies in the complex vision process.

The main parts of the human eye include:

  • Cornea: transparent tissue covering the front of the eye that lets light travel through
  • Iris: a ring of muscles in the colored part of the eye that controls the size of the pupil
  • Pupil: an opening in the center of the iris that changes size to control how much light is entering the eye.
  • Sclera: the white part of the eye that is composed of fibrous tissue that protects the inner workings of the eye
  • Lens: located directly behind the pupil, it focuses light rays onto the retina
  • Retina: membrane at the back of the eye that changes light into nerve signals
  • Rods and cones: special cells used by the retina to process light
  • Fovea: a tiny spot in the center of the retina that contains only cone cells. It allows us to see things sharply.
  • Optic Nerve: a bundle of nerve fibers that carries messages from the eyes to the brain
  • Macula: a small and highly sensitive part of the retina responsible for central vision, which allows a person to see shapes, colors, and details clearly and sharply.

 

Special thanks to the EyeGlass Guide, for informational material that aided in the creation of this website. Visit the EyeGlass Guide today!

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To our valued patients,

At The Eye Doctors, Inc. the health and well-being of our patients is at the core of everything that we do. In light of the rapidly changing situation and the spread of COVID-19 we made the difficult decision to close the clinic on Tuesday, March 17 th.

At this time, the Wal-Mart Vision Center remains open limited hours for urgent glasses repairs, pick-ups of existing orders and new contact lens orders. The vision center is open every day from 10 AM to 2 PM and on Tuesdays from 6 AM to 2 PM, with the hour of 6 AM to 7 AM reserved for senior citizens.

If you are experiencing an eye emergency, please call 952-955-4427 to leave a message for one of the doctors. Messages will be checked Monday through Saturday from 9 AM to 5 PM.

We are monitoring the situation closely and will re-open when it is safe to do so. We look forward to seeing you when things improve and thank you for your continued support of our practice. Please continue to our website for further information.

Dr. Melissa Viker & Dr. Britt Gustafson

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The Eye Doctors, Inc. COVID-19 Information:

Our clinic closed on March 17th and will remain closed until it is safe to re-open.  Please watch our website and Facebook page for updates.

Urgent or Emergent Eye Concerns

If you have an eye emergency, we are here to help.  Please call 952-955-4427 and one of the doctors will return your call.  The messages are monitored Monday through Saturday between 9 AM and 5 PM.  Eye emergencies include (but are not limited to): eye pain, a recent onset of redness in one or both eyes, flashes of light or sudden onset of new floaters, double vision, and sudden change/worsening of vision in one or both eyes.

Glasses and Contact Lens Orders:

The Wal-Mart Vision Center is open daily at this time from 10 AM to 2 PM and 6 AM to 2 PM on Tuesdays for limited services. The hour of 6 AM to 7 AM on Tuesdays is reserved for senior citizens.  One optician is on duty to provide urgent glasses repairs and adjustments; at this time no new orders for glasses are being accepted. Existing orders of contact lenses and glasses may be picked up from the vision center.  New orders of contact lenses can be placed in store and will be shipped to your home if we do not have the lenses in stock. Additionally, you may order contact lenses at www.walmartcontacts.com

Contact Lens Safety

There is no evidence that contact lens wearers are at greater risk for a Corona Virus infection, per the American Optometric Association Cornea and Contact Lens Section.  Please follow the below tips:

  • Wash and dry your hands thoroughly before handling contact lenses
  • Avoid using contact lenses if you are ill with any cold or flu-like symptoms
  • Reduce your risk for infection by avoiding sleeping, napping, swimming or showering in contact lenses
  • Replace your contact lens case every 2 months
  • Use fresh contact lens solution each time you store your lenses
  • Do not reuse single-use/daily disposable lenses