Understanding How Your Vision Works

Your vision is achieved through a complex process involving eye structures, nerves, and the brain working together to create sight. If any structure of the eye becomes damaged, it can affect vision.

Learning how your vision works is helpful in understanding various types of vision disorders, such as refractive disorders.

Keep reading below to learn more about how vision works and what refractive disorders are.
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Eye anatomy: parts of the eye

Learning more about the anatomy of the eye is the first step in understanding how vision works. The anatomy of the eye includes:

• Cornea: The cornea is the clear layer at the front of the eye. It is dome-shaped and bends light, helping the eye focus.
• Iris: The iris surrounds the pupil and is the colored part of the eye. It controls the amount of light that enters the eye.
• Pupil: The pupil is in the center of the iris, through which light passes.
• Lens: The lens sits behind the iris and helps direct light onto the retina.
• Retina: The retina is the light-sensitive tissue at the back of the eye that sends signals to the brain to create visual images.
• Optic nerve: Think of the optic nerve as the transporter that sends signals to different parts of your brain that create the images you see.

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How does vision work?

The parts of the eye listed above work together in a complex process that creates images by using chemical and electrical signals.

The process starts as light passes through the cornea. Some of that light enters through the pupil and passes through the lens.

With help from the cornea, the lens focuses light on the retina, which contains photoreceptor cells. When light hits these cells, a physiological reaction occurs, causing the cells to convert light into nerve signals. These signals travel through the optic nerve to the brain, which converts them into the images we see.

The brain takes messages from the optic nerve and decodes the signals. The brain uses that information to create an image of what your eyes see.
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What are refractive errors? 

Various conditions can affect the visual process described above. One common condition is refractive errors. Refractive errors occur if the shape of the eye prevents light from focusing directly on the retina. This can cause a variety of symptoms, including blurry vision.

A refractive error may occur if the lens is thicker or thinner than normal or if the eye is too long or short. It can also occur in people with a naturally flatter or steeper eye surface.

There are different types of refractive errors, including the following:
Myopia: Doctors commonly refer to this as nearsightedness. People with myopia have trouble seeing distant objects.
Hyperopia: This is farsightedness. Individuals who have hyperopia have trouble seeing objects that are close.
Astigmatism: Astigmatism causes blurry vision in objects up close and at a distance.
Presbyopia: This type of refractive error develops because of normal age-related changes to the eye. It causes close objects to appear out of focus.

Refractive errors are widespread and treatable. It's important to see an eye specialist to determine the specific vision issue you have and get appropriate treatment.

We are happy to answer any questions you may have about refractive errors. Also, if you would like to ask whether an appointment with one of our eye doctors would be appropriate at this time, call our office at 508-746-8600.