The Science Behind Perfect Eyesight

Image of an eye.

It's easy to take vision for granted when the eyes perform flawlessly. However, when eye problems crop up, it's hard not to wonder how the eyes work. In a properly functioning eye, a number of elements must cooperate perfectly to create good vision; just one malfunctioning factor in this instantaneous process can cause blurry vision, pain or even blindness. The entire field of optometry is dedicated to managing vision problems and determining the best method of correcting poor vision.

The Birth of a Picture

Vision begins when light rays are reflected off objects and into the eyes via the cornea, a transparent bulge that covers the front of the eyeball. The cornea refracts, or bends, the light rays so that they pass through the dark, small round hole, called the pupil. The amount of light permitted to enter the pupil is regulated by the iris, the colored part of the eye that changes the size of the iris.

After passing through the pupil, the light rays shine through the lens. This remarkable component changes it shape to bend the rays as needed to focus them on the retina located at the back of the eyeball.

Translating the Picture

The retina is composed of millions of two types of nerve cells that detect the light. Cones are found primarily in the center of the retina, in a region called the macula, and specialize in sharp vision with fine details and colors. Rods reside beyond the macula to provide peripheral (side) vision, detect motion outside the central vision, and provide vision in dim or dark lighting conditions.

Decoding the Message

Both cones and rods convert the received light rays into specific patterns of electrical impulses to be delivered to the brain through the optic nerve. In the brain, the impulses are assembled and decoded to form an image.

When Things Don’t Line Up

The overall shape of the eyeball ultimately determines how well the eye can focus and receive the incoming image; when a patient experiences poor or blurry vision, an optometrist exams the eye to figure out what went wrong.

Normally, the eye retains a spherical shape. If the shape changes, such as with an elongated eyeball, the cornea's curvature will no longer focus the incoming light rays appropriately to match the distance from the lens to the retina.

Consultation with an optometrist can determine whether corrective lenses or surgery are needed to restore properly focused vision.

Sources:

American Optometric Association (2013). How Your Eyes Work.


Ask about our BOGO Deal!

Qualifying contact lens purchases are eligible for FREE polycarbonate single vision lenses

Hours of Operation

Our Regular Schedule

Pittsburg

Monday:

8:00 am-5:00 pm

Tuesday:

8:00 am-5:00 pm

Wednesday:

8:00 am-7:00 pm

Thursday:

8:00 am-5:00 pm

Friday:

8:00 am-5:00 pm

Saturday:

8:00 am-12:00 pm

Sunday:

Closed

Girard

Monday:

10:00 am-12:00 pm

1:00 pm-7:00 pm

Tuesday:

8:30 am-12:00 pm

1:00 pm-4:30 pm

Wednesday:

8:30 am-12:00 pm

1:00 pm-4:30 pm

Thursday:

8:30 am-12:00 pm

1:00 pm-4:30 pm

Friday:

Closed

Saturday:

Closed

Sunday:

Closed

Fort Scott

Monday:

8:00 am-12:00 pm

1:00 pm-5:00 pm

Tuesday:

8:00 am-12:00 pm

1:00 pm-5:00 pm

Wednesday:

8:00 am-12:00 pm

1:00 pm-5:00 pm

Thursday:

8:00 am-12:00 pm

1:00 pm-5:00 pm

Friday:

8:00 am-12:00 pm

1:00 pm-5:00 pm

Saturday:

Closed

Sunday:

Closed

Locations

Find us on the map

  • "We see Dr.Kannar & Dr.Jacquinot often, myself, my husband and my son love them both and their staff. They are all great people! I highly recommend them!"
    Heather P.
  • "Dr Painter see both my husband and myself she is very pleasant and takes very good care of us she always take time to explain and makes sure our needs our taken care of."
    Brenda B.
  • "I went to the office in Girard and saw Dr Painter. The whole office is Wonderful! Very friendly and caring. My glasses are perfect! Won't go anywhere else!"
    Linda M.
  • "Pittsburg is lucky to have you Dr. Kannarr (as am I ) Thanks for everything you do for your patients!"
    Becky O.

Featured Articles

Read up on Informative Topics

  • Dry Eye

    Sometimes your eyes don’t make enough tears or the tears evaporate too fast because they don’t have the right amount of compounds in them. This is called dry eye. Up to 5% of Americans complain of some form of dry eye. Individuals who wear contact lenses or have undergone LASIK or other types of ...

    Read More
  • Subconjunctival Hemorrhage

    Similar to a bruise under the skin, a subconjunctival hemorrhage happens when a small blood vessel located between the sclera (white portion of an eye) and the conjunctiva (lining on the surface of an eye) breaks and covers the sclera with blood. Unlike broken blood vessels located under the skin which ...

    Read More
  • Decorative (Plano) Contact Lenses

    Colored contact lenses allow you to temporarily change your eye color whether or not you need to correct impaired vision. In this way, you can create a more subtle eye appearance, wear a crazy design for special occasions, or just enjoy a new eye color. Will Colored Contacts Change the Way I See? Yes, ...

    Read More
  • Wandering Eye

    A wandering eye is a type of eye condition known as strabismus or tropia, and it may be caused by damage to the retina or muscles that control the eye, stroke or brain injury, or an uncorrected refractive error like farsightedness. With a wandering eye, one eye deviates or wanders in a different direction ...

    Read More
  • Reading and Writing

    For many adults, reading and writing come so naturally that they seem almost effortless. However, reading and writing are actually complicated skills that take significant effort to learn. For example, reading involves recognizing letters, associating letter combinations with their corresponding sounds, ...

    Read More
  • Lazy Eye

    Lazy eye, also referred to as amblyopia, is a condition that develops in infancy or early childhood, and it typically starts when the focus in one eye is more enhanced than the other. The eye with less focus might be impaired due to a significant amount of farsightedness or astigmatism, or something ...

    Read More
  • Dyslexia

    Dyslexia When a child has difficulty reading due to problems recognizing speech sounds and learning how they connect to words and letters, the condition is known as dyslexia, a learning disorder caused by genetic traits that disturb how the brain works. It affects areas of the brain dealing with language ...

    Read More
  • Crossed Eyes

    Crossed eyes, also known as strabismus, refer to a condition in which both eyes do not look at the same place at the same time. Often times they both turn in, but may also turn out. What Causes Crossed Eyes? The six muscles attached to each eye, which control how it moves, receive signals from the brain. ...

    Read More
  • Autism

    Symptoms and Problems Caused By Autism Autism is a neurological disorder in which the person has difficulty processing and reacting to information received from their senses. The individual also has trouble communicating and interacting socially. Signs of autism include: Lack of shared social interaction Postponement ...

    Read More
  • ADD/ADHD

    Approximately 11% of school-aged children have been diagnosed with attention deficit/hyperactivity disorder (ADHD), according to recent studies. The central symptoms of ADHD -- difficulty sustaining attention, poor control of behavior, hyperactivity -- make it difficult for children to succeed in school. ...

    Read More

Newsletter Sign Up