How do you see?

The video, "How do you see?" by Stephanie McQuaid, demonstrates how the visual system functions. The video is intended for children between the ages of eight to eleven. This is the equivalent for children in second to fifth grade. The visual system is one of the most vital systems for survival. The eye needs light to see an object or dangers ahead of it. Once the light hits the object that light bounces off the object and into the eye. The light passes through the cornea; the clear part, the pupil; the hole to the eye, which its size is controlled by the iris; the colored part of the eye. Once the light passes through the pupil it hits the lens and is reflected on the back of the eye upside down. The eye sees the image upside down but the brain corrects this image as right side up. On the back of the eye the photoreceptors; the rods and cones, are stimulated by the light energy and that light energy is converted into an electrical impulse. Once the cells are excited the impulse travels down the optic nerve and to the visual cortex, or occipital lobe; this is the part of the brain that interprets what the eyes see. The brain sorts through the pieces that it receives from the photoreceptors and creates an image. The final image is then interpreted and categorized for future encounters. This is how an individual can see.



References
7 Active (2013, January 4). The Human Eye [Video file]. Retrieved from http://www.youtube.com/watch?v=nbwPPcwknPU

Bausch and Lomb (2010, August 3). A Journey Through the Human Eye: How We See [Video file]. Retrieved from http://www.youtube.com/watch?v=gvozcv8pS3c

Chudler , E. H. (2010). Neuroscience For Kids - The Eye. Retrieved November 20, 2013, from http://faculty.washington.edu/chudler/bigeye.html

KidsHealth (2013). Eyes. Retrieved November 19, 2013, from http://kidshealth.org/parent/general/body_basics/eyes.html

National Eye Institute (2013). See All You Can See :: Visual System, How the Eye Works :: NEI. Retrieved December 2, 2013, from http://isee.nei.nih.gov/parts/visualsystem.asp

The Science Museum Group (2013). How do you see? Retrieved November 20, 2013, from http://www.sciencemuseum.org.uk/whoami/findoutmore/yourbrain/whatareyoursenses/howdoyousee.aspx

Than , K. (2005, November 28). How the Human Eye Works | LiveScience. Retrieved November 21, 2013, from http://www.livescience.com/3919-human-eye-works.html

Women's and Children's Health Network (2012, September 11). Kids' Health - Topics - Eyes - how your eyes work. Retrieved November 19, 2013, from http://www.cyh.com/HealthTopics/HealthTopicDetailsKids.aspx?p=335&np=152&id=1730