How the Eyes Work

Vector image of an eyeball.

Every morning, we open our eyes and become immersed in a wealth of visual information. The eyes and related brain structures are a complex system that allows us to experience visual information from the surrounding world. It is easy to take clear vision for granted, but even subtle changes in the structure or functioning of the eyes can disrupt our sight. An eye care provider conducts a thorough eye exam to ensure that these components are functioning together well.

Basic Eye Anatomy

The eyeball is not a single, spherical structure as is commonly thought. It consists of a smaller, curved portion called the cornea that attaches to a larger, roughly spherical structure called the sclera (the white of the eye). The eyeball is filled with a jelly-like substance called the vitreous fluid.

Toward the front of the eye are three essential structures: the iris, pupil, and lens. The iris is the colored part of your eye. It can open and close to determine how much light to let in through the pupil, the black hole in the center of your eye. Finally, the lens is a flexible, convex structure that changes shape to direct light rays in different directions within the eye.

At the back of the eyeball is a layer of tissue called the retina. The retina consists of millions of photosensitive cells that react to certain types of light. Cone cells are clustered toward the center of the retina, and react to colors and details in bright light. Rod cells, which are spread toward the periphery of the retina, react to dim lighting conditions.

How the Eyes Facilitate Vision

When light enters the eye through the pupil, it passes through the lens, which changes shape to ensure that the light rays hit the retina. When the light rays reach the back of the eye, it stimulates the rod and cone cells to fire. Cone cells detect fine details and color in the center of your visual field. Rod cells detect edges in peripheral vision and allow us to perceive shapes in dim light.

The rods and cones in your retina convert light energy into electrical signals, which exit the eye through the optic nerve, located just below the center of the retina. The optic nerve carries visual information to the occipital cortex in the very back of your brain, where it is processed to result in a rich visual experience.

If any part of this complex arrangement functions improperly, vision is impaired. Thus, it is essential to receive regular optometry exams to have your eye structures and visual abilities checked.

Contact Us

We look forward to hearing from you.

Hours of Operation

Our Regular Schedule

Harlingen Eye Clinic

Monday:

8:30am

5:30pm

Tuesday:

8:30am

5:30pm

Wednesday:

8:30am

5:30pm

Thursday:

8:30am

5:30pm

Friday:

8:30am

5:30pm

Saturday:

9:00am

12:00pm

Sunday:

Closed

Closed

Location

Find us on the map

Testimonial

  • "I will be going to him for future eye care needs and would recommend him to anyone who cares about their eye sight."
    Louis P. / -Harlingen, TX

Featured Articles

Read up on informative topics

  • Frequently Asked Questions

    Why do I need to see an eye care provider? Many “silent” diseases, such as glaucoma and diabetes, can only be detected through regular eye exams. When these conditions are discovered earlier rather than later, they become easier to treat or manage, allowing for better long-term preservation of eyesight. ...

    Read More
  • Pediatric Ophthlamology

    Ophthalmology addresses the physiology, anatomy and diseases of the eyes. Pediatric ophthalmology focuses on the eyes of children. Pediatric ophthalmologists examine children’s eyes to see if they need corrective lenses or other treatments to improve their vision. Training for Pediatric Ophthalmologists Pediatric ...

    Read More
  • Allergies

    Caused by the same irritants as hay fever, runny nose, coughing, and sneezing, eye allergies commonly affect those who suffer from other allergy symptoms. Not only do eye allergies cause discomfort, but they can also interfere with daily activities. Eye Allergy Causes Medically referred to as allergic ...

    Read More
  • Learning-Related Vision Problems

    Learning disabilities may include dyslexia, math disorder, writing disorder, auditory processing deficits, or visual processing deficits. Although each child with a learning disability is unique, many also have associated visual problems. Addressing these vision disorders may alleviate some symptoms ...

    Read More
  • UV Radiation and Your Eyes

    Optometry warnings about the damaging effects of ultraviolet radiation on our eyes have not yet reached the degree of public awareness of that of skin damage. Yet, the sun can be just as damaging upon our eyes with unprotected exposure. Short-term exposure to very bright sunlight can result in a type ...

    Read More
  • How To Protect Your Eyes While Wearing Halloween-Themed Contact Lenses

    Spooky novelty contact lenses can make your Halloween costume even scarier, but are they safe? ...

    Read More
  • Fuchs' Corneal Dystrophy

    Fuchs' dystrophy (pronounced fooks DIS-truh-fee) is an eye disease characterized by degenerative changes to the cornea’s innermost layer of cells. The cause for Fuchs' dystrophy is not fully understood. If your mother or father has the disease, then there is roughly a 50 percent chance that you will ...

    Read More
  • Age-Related Macular Degeneration

    One of the leading causes of vision loss in people who are age 50 or older is age-related macular degeneration (AMD). This common eye condition leads to damage of a small spot near the center of the retina called the macula. The macula provides us with the ability to clearly see objects that are straight ...

    Read More
  • Diabetic Eye Diseases

    Diabetes is a condition that involves high blood sugar (glucose) levels. This can affect many parts of the body, including the eyes. One of the most common diabetic eye diseases is diabetic retinopathy, which is also a leading cause of blindness in American adults. Diabetic Retinopathy Diabetic retinopathy ...

    Read More
  • Presbyopia

    Somewhere around the age of 40, most people’s eyes lose the ability to focus on close-up objects. This condition is called presbyopia. You may start holding reading material farther away, because it is blurry up close. Reading suddenly gives you eyestrain. You might wonder when manufacturers started ...

    Read More

Sign up for alerts and newsletters!