How the Eye Works: The Basics of Vision
The eye contains may different parts that work together to make vision possible. Many people do not understand how the eyes work, however. A lack of understanding about the parts and function of the eyes could make retinal diseases and conditions like tears of detachment seem confusing.
Dr. David J. Parks take time with patients at his Beverly Hills, CA office to go over the basics of vision. Right now, the Pacific Retina Specialists team would like to cover how the eye works in simple terms.
The Parts of the Eye
Before getting into the way the eye works, let’s go over the parts of the key parts of the eye:
- The Cornea - The cornea is the clear, dome-like outer surface of the eye.
- The Sclera - The sclera is the white part of the eye.
- The Iris - The iris is the colored part of the eye.
- The Pupil - The pupil is the dark circular opening in the iris.
- The Lens - The lens is located inside the eye and is important for focusing light.
- The Vitreous - The vitreous is the clear, gel-like substance inside of the eye.
- The Retina - The retina is the light-sensitive tissue at the back of the eye.
- The Optic Nerve - The optic nerve carries light signals to your brain.
Now knowing all of the parts of the eye, let’s get into the basics of how vision works.
Light Enters the Eye
Light first passes through the cornea, which bends the light in a manner such that it can enter the pupil. If there is too little or too much light, the iris can open or close to allow more light or less light in.
As the light enters the pupil, it then hits the lens of the eye. Like the lends of a camera, the eye’s lens can lengthen or shorten its width in order to properly focus the light.
Light and the Retina
After being focused by the lens of the eye, the light passes through the vitreous gel, the substance that allows the eye to maintain its round shape. The light is all focused to a point on the retina.
The retina has many parts, but the key one we want to focus on are the photoreceptor cells. There are two kinds of photoreceptors: rods and cones. Rods work with low light levels and are essential for night vision. Cones are essential for color vision. There are three kinds of cones: red, blue, and green. The human eye contains about 6 million cones.
The Optic Nerve and the Brain
The rods and cones in the retina help interpret the light signals that travels through the eye. These light signals are interpreted into millions of light signals that are sent into the optic nerve. All of these visual signals are then relayed to the brain to be interpreted into images.
What Does This Mean About Vision Problems?
As you can imagine, the with so many different parts of the eye, visions problems can occur when one part or multiple parts of the eye no longer function properly. Problems with the cornea, for instance, can result in refractive errors such as myopia (nearsightedness), hyperopia (farsightedness), and astigmatism. Issues with the retina could result in major vision problems since the photoreceptors could be damaged or not functioning properly.
During an eye exam, we will be sure to perform a full eye exam and look at all of the parts of your eye to figure out what problem(s) you may be experiencing.
Learn More About Vision Care and Eye Health
To learn more about eye health and your vision, we encourage you to contact Pacific Retina Specialists. Our team is here to provide you with answers to your questions and information on your concerns. You can also reach our office by phone at (310) 289-3666.
