Our Vision Process by Brenden Hall

    

             Human vision can be very complex and hard to understand. As humans we need the ability to see, to cope with our surroundings, but do we know how vision genuinely works? There are various steps required for the eye to form the images people see.

            First, the eye must gather light. Light rays are reflected off an object and enter the eyes through the cornea, which allows people to see that object. The cornea bends the rays that pass through the round hole of the pupil. The iris opens and closes, making the pupil bigger or smaller (American Optometric Association, n.d.).

When the pupil changes in size it means that it is regulating the amount of light being passed through the pupil. So when light passes through the pupil it first hits the lens. The lens is similar to a magnifying glass that reflects the light toward the back of our eye. The lens is constantly changing shape depending on whether we are looking at objects close to us or far away (Vision, n.d.).

Once the lens changes shape so it can bend the rays and focus the shape on the retina. The retina is the part of the eye that sits in the back, it is a thin layer of tissue that consists millions of tiny light-sensing nerve cells. These nerve cells are called rods and cones because of their noticeable shape (American Optometric Association, n.d.). Rods and cones are the first layer of cells to be activated by light. Rods see only black and white and are spread throughout the outside of the retina. Whereas cones see color and are located in the center of the retina known as the fovea. Since cones are located in the fovea humans see color objects better if they are directly in front of us. As for cones, they are located on the periphery of the retina we see black and white better in our peripheral vision (Vision, n.d.). These two distinguishable cells in the retina convert the light into electrical impulses, the optic nerve sends these impulses to the brain, which produces an image that allows humans the capability to see.

 

References

American Optometric Association (n.d.). How your eyes work. Retrieved April 18, 2017, from http://www.aoa.org/patients-and-public/resources-for-teachers/how-your-eyes-work?sso=y

Vision (n.d.). Retrieved April 18, 2017, from http://www.appsychology.com/Book/Biological/vision.htm