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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!

Dear valued patient,

We take our commitment to keeping our patients and team safe and healthy inthe midst of this COVID-19 pandemic very seriously. We want to share our plan to comply with social distancing guidelines for your upcoming appointment. Please carefully read the steps below and follow our direction when you arrive. Our team will all be wearing masks and we ask that you bring one with you to wear during your visit (for everyone’s safety, we are requiring staff and patients to wear masks).

We ask patients to complete necessary paperwork online if possible. Click here to access the forms. You may also choose to text a photo of your insurance card and photo ID to the clinic at 763-537-3213.

When you arrive for your appointment, enter the main doors and wait in the front alcove until a staff member greets you. Our front desk team will ask you general health questions to rule out the presence of COVID-19 symptoms.

We are asking that only the patient enter the building for the exam. (Exceptions: Children under 18 may be accompanied by one guardian, and adults with special needs may be accompanied by one caretaker.)

When you enter the building:

Staff will ask you to use hand sanitizer and then you will complete any necessary paperwork that you were not able to complete online, and we will make copies of your insurance card and photo ID if you did not text a picture of them to us.

Prior to seeing your doctor, a technician will escort you to a pre-testing room where you will be asked to wash your hands. We ask that you follow the CDC’s recommendation of washing your hands thoroughly, for a full 20seconds, with soap and water.

Rest assured that every surface and every piece of equipment you come into contact with has been sanitized prior to the arrival of each and every patient entering our practice, and it will be cleaned again as you exit each area.

The team will be frequently washing their hands between interactions as per our usual protocol, and you’ll also see hand sanitizer throughout the practice for your use, as well.

Optical – Shopping for Glasses, Adjustments and Repairs, and Glasses Pick-up

We are scheduling appointments for all optical needs. Please call the clinic at 763-537-3213 to schedule your appointment.

When you are shopping for glasses, one of our ABO certified opticians will ask you to be seated at a station where you will discuss your needs, likes and dislikes. To ensure social distancing, the optician will bring frames to you so you can try them on at the station. The optician will continue to bring frames to you until you find the perfect pair!

We sterilize every frame a patient touches in a UV Cleaning Unit after a shopping appointment so you can be assured any frame you try on has been sanitized prior to your visit.

If you have any questions or concerns, please don’t hesitate to call us. We look forward to seeing you!

Thank you for your patience and cooperation,

Your Crystal Vision Clinic Eye Care Team

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We sterilize every frame a patient touches in a UV Cleaning Unit after each shopping appointment so you can be assured any frame you try on has been sanitized prior to your visit.