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8220 Louetta Road, Suite 112
Spring, TX 77379

281-370-2020
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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!

Klein Eyecare update for COVID-19 (3/20/20)

As we all navigate the unprecedented pandemic facing our country, we would like you to know that the safety of our patients and our staff are of utmost importance to us as we simultaneously continue to care for your eye care needs.  For this reason, we have implemented an extremely rigorous sanitization program and have dramatically reduced the number of people and patient encounters in the office.  We will be open and continue to offer eye care services during this time under the following circumstances:

We will be available for any eye care service that either the patient or our office feels is of any sort of urgent nature.  (Examples could be eye infections, decreased vision, lost or broken glasses, sudden or recent change of vision or prescription, flashes or floaters, or any other reason that our patients feel they need to be seen.)  Patients may be asked to wait in their cars until we call each patient back to maintain adequate social distancing.  We will also ask each patient to wash their hands before being seen. 

We will not be seeing anyone with a fever, anyone that has been in contact with anyone who has been ill, or anyone who has traveled out of the country in the last two weeks.

We will extend contact lens prescriptions for a limited time and will offer free shipping to your home/office.

We will be available for glasses pick-ups by appointment only.  We will not be adjusting glasses at this time, but we do recommend coming back for adjustments once this situation clears.  We will also be happy to deliver them to your car.

Our office remains open with some adjustments to our hours and staffing.  We are here if you have any questions, concerns, or need to make any contact lens orders.  We will also continue to provide updates as the situation evolves.

Regards,

Richard Scott, OD

Grant Gibson, OD

Lance Abernathy, OD


Do you have enough contacts???

With the day to day changes surrounding COVID-19, we know that many of you may be concerned that you have enough contact lenses. With that being said if you are a contact lens wearer and currently have less than a 3 month supply left, we highly recommend that you place an order now. We will ship them directly to you at no charge.  We will extend contact lens prescription expiration dates as needed. 

Call 281-370-2020 to place your order.