How does sight occur

This is why keeping your eyes in good condition should always be a priority. Today, Park Slope Eye, your trusted family eye care clinic, explains the vision process. Your capacity to see stems from complex teamwork between your eyes and brain. The vision process starts when light rays from the objects you see pass through the cornea, the clear, dome-like structure covering your eyes. These light rays will then enter a black opening called the pupil.

The size of your pupil is controlled by the iris, the colorful part of your eyes. Afterward, the light rays are bent toward your lenses. Once the light rays reach the back part of your eyes, the retina will then convert them into nerve impulses, with the assistance of light-sensitive photoreceptors.

The optic nerve will then deliver these signals to your brain, which translates them into the images you see.

Any irregularities with your eye structures or the image translation process may lead to vision problems, such as refractive errors. Your eye doctor will assess your eye health and vision and provide various options to keep you seeing clearly.

Your plain English library for vision therapy, children's vision, neuro-optometry, and primary eye care. Find an Eye Doctor. Search near me. Russel Lazarus, October 11, Approximately 80 percent of everything we learn comes through our eyes — the question is, how?

In order to produce a clear image, the eyes must complete a five step process: Step 1: Light enters the eye through the cornea When we look at an object, the light that is reflected off of the object enters the eye through the clear front layer of the eye, called the cornea. Step 2: The pupil adjusts in response to the light The light continues to travel through the black opening in the center of the iris, called the pupil.

The pupil then automatically gets bigger or smaller, depending on the intensity of the light. How does the pupil expand and contract? Step 3: The lens focuses the light onto the retina The light passes through the pupil to the lens behind it. Next Article Nearsighted or Farsighted? Find an Eye Doctor Search near me. Vision begins with light passing through the cornea and the lens, which combine to produce a clear image of the visual world on a sheet of photoreceptors called the retina.

As in a camera, the image on the retina is reversed: Objects above the center project to the lower part and vice versa. The information from the retina — in the form of electrical signals — is sent via the optic nerve to other parts of the brain, which ultimately process the image and allow us to see. Thus, the visual process begins by comparing the amount of light striking any small region of the retina with the amount of surrounding light.

Visual information from the retina is relayed through the lateral geniculate nucleus of the thalamus to the primary visual cortex — a thin sheet of tissue less than one-tenth of an inch thick , a bit larger than a half-dollar, which is located in the occipital lobe in the back of the brain. The primary visual cortex is densely packed with cells in many layers, just as the retina is.

In its middle layer, which receives messages from the lateral geniculate nucleus, scientists have found responses similar to those seen in the retina and in lateral geniculate cells. The optic nerve will send this information to your brain. It is responsible for decoding the electrical information coming from the retina.

The vision center interprets the electric form of the image, allowing you to form a visual map. As you can SEE , vision is a complex process. The brain has to do a lot of work to make a picture. But what happens if what you see is blurry? Maybe you or someone you know may need to wear glasses or contacts in order to see clearly.

You may even know someone who is blind and cannot see at all. How do you think they see the world? Page Baluch, Ashleigh Gonzales. How Do We See?. Do insects see the same thing you do? Visit insect vision to learn more. Human Eye Worksheet. Putting the Touch into Biology. By volunteering, or simply sending us feedback on the site. Scientists, teachers, writers, illustrators, and translators are all important to the program. If you are interested in helping with the website we have a Volunteers page to get the process started.

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