Students examine the structure and function of the human eye, learning some amazing features about our eyes, which provide us with sight and an understanding of our surroundings. Students also learn about some common eye problems and the biomedical devices and medical procedures that resolve or help to lessen the effects of these vision deficiencies, including vision correction surgery.
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- Colorado: Science
- b. Develop, communicate, and justify an evidence-based scientific explanation regarding the functions and interactions of the human body (Grade 7)  ...show
- Common Core State Standards for Mathematics: Math
- 4. Display numerical data in plots on a number line, including dot plots, histograms, and box plots. (Grade 6)  ...show
- c. Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent. (Grade 6)  ...show
- International Technology and Engineering Educators Association: Technology
- G. Advances and innovations in medical technologies are used to improve healthcare. (Grades 6 - 8)  ...show
- Next Generation Science Standards: Science
- Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions. (Grades 6 - 8)  ...show
- Explain how the cornea is altered during vision correction surgery.
- Describe several biomedical devices used today to correct and improve our vision, identify constraints to the problem, and explain how they are used.
- Explain how biomedical engineers can help people who have problems with their eyesight.
- With astigmatism, a person's cornea is not evenly round, which causes light to focus at different distances inside the eye. When looking at an object, some parts may be in focus, while other parts are blurry. To correct this problem, the cornea must be reshaped to be more spherical, so as to correctly focus light on the retina.
- Nearsightedness is the inability to clearly distinguish objects at a distance. This happens when a person's eyeball shape is long, causing light to focus in front of the retina. To correct this, a person must either wear glasses or reshape the cornea to be flatter so that light travels through the lens and focuses correctly on the retina.
- Farsightedness is the inability to clearly distinguish objects up close. This happens when a person's eyeball shape is short (having too flat of a cornea), causing light to focus behind the retina. To correct this, a person must either wear glasses that cause the light to focus sooner or reshape the cornea to be more rounded so that light focuses correctly on the retina.
Lesson Background and Concepts for Teachers
Parts of the Eye
More Cool Biomedical Devices for the Eye
|biomedical engineer:||A person who blends traditional engineering techniques with the biological sciences and medicine to improve the quality of human health and life. Biomedical engineers design artificial body parts, medical devices, diagnostic tools, and medical treatment methods.|
|conjunctiva:||The thin transparent tissue on the outer surface of the eye that covers the visible part of the eye and lines the eyelids.|
|choroid:||A layer of the eye that lines the back of the eye, containing many tiny blood vessels that nourish the retina,|
|constraint:||A restriction or limitation.|
|cornea:||The clear, dome-shaped window on the front of the eye. The cornea provides 2/3 of the eye's focusing power. It refracts light towards the lens.|
|gene:||Information about or physical characteristics carried through DNA.|
|iris:||The colored ring that surrounds the pupil. The iris has many tiny muscles that control the size of the pupil, thus regulating the amount of light entering the eye.|
|LASIK:||Acronym for laser-assisted in situ keratomileusis, a procedure that permanently changes the shape of the cornea an excimer laser.|
|lens:||The clear disc behind the iris that helps to focus light, or an image, on the retina (the back of the eye). It is suspended by fibrous strands called zonules.|
|macula:||The small sensitive area of the retina that gives central vision. It is located in the center of the retina and contains the fovea (the center of the macula, giving the sharpest vision).|
|optic nerve:||A bundle of more than one million nerve fibers that carries visual messages from the retina, in the back of the eye, to the brain.|
|peripheral vision:||Seeing things to the sides of the area on which you are focusing. This vision is most sensitive to shapes and movement; objects seen are not in focus.|
|photodiode:||An electrical device that uses light to create an electrical current.|
|pupil:||The black, circular opening in the center of your eye (in the center of the iris) that permits light to enter. The iris adjusts the size of the pupil to control the amount of light that enters the eye. It dilates (becomes larger) in low light to let in more of the available light and constricts (becomes smaller) in bright light.|
|refract:||To change the direction of light passing through.|
|retina:||A thin, light-sensitive tissue lining at the back of the eye that converts light focused on the retina from the lens into electrical impulses that are sent to the brain through the optic nerve.|
|sclera:||The white outer surface of the eye. The sclera is a tough, opaque tissue that protects the inner parts of the eye.|
|ultraviolet light:||Ultraviolet (UV) light travels at a higher frequency than violet light. It is not visible with the human eye. It can cause "sunburn" if exposed for a long period of time.|
|vitreous:||A clear gel that fills the inside of the eyeball. Composed mostly of water, it accounts for about 2/3 of the eye's volume, and gives it shape.|
- Protect Those Eyes - With a specific sport or activity in mind, student teams design and create prototypes for protective eyewear. Students consider possible eye hazards and how engineers incorporate different features and materials into designs to protect the eyes from these risks.
Lesson Summary Assessment
Lesson Extension Activities
Additional Multimedia Support
Anitel, Stefan. "11 Amazing Facts and Myths about Eyes (More Complex than a Photo Camera)" Published December 27, 2007. Softpedia. Accessed February 11, 2009. http://news.softpedia.com/news/10-Amazing-Facts-and-Myths-About-Eyes-74813.shtml
Bausch and Lomb. Retisert (fluocinolone acetonide intravitreal implant) Patient Section Home. 2006. Accessed February 11, 2009. http://www.retisert.com/patient_home.html
Diagram of the Eye. Last modified October 2008. National Eye Institute, National Institutes of Health. Accessed February 11, 2009. (source of some vocabulary definitions, with modifications) http://www.nei.nih.gov/health/eyediagram/index.asp
Eye Anatomy: Parts and Functions. St. Luke's Cataract and Laser Institute. Accessed November 3, 2010. http://www.stlukeseye.com/anatomy/
Hartong, D.T., Berson, E.L. and Dyria, T.P. Retinitis Pigmentosa. Published November 18, 2006. Lancet 368 (9549); 1795-809. PubMed.gov, NCBI, NLM, National Institutes of Health. Accessed February 11, 2009. http://www.ncbi.nlm.nih.gov/pubmed/17113430
Learning about LASIK. Updated September 18, 2008. US Food and Drug Administration and Center for Devices and Radiological Health, US Department of Health and Human Services. Accessed February 11, 2009. http://www.fda.gov/
McNeely, Gretchen. "Optobionics stays focused as retina implant process plods along." Published June 16, 2003. Small Times. Accessed February 11, 2009. http://www.smalltimes.com/Articles/Article_Display.cfm?ARTICLE_ID=268807&p=109
Tyson, Jeff. How LASIK Works. September 19, 2001. HowStuffWorks.com. Accessed February 11, 2009. http://health.howstuffworks.com/lasik.htm
Understanding LASIK. The Vision Correction Website. Internet Media Service Inc. Accessed February 11, 2009. (good description and diagrams of surgery steps, plus link to video) http://www.lasersite.com/lasik/index.htm
William Surles, Lesley Herrmann, Malinda Schaefer Zarske, Denise W. Carlson
© 2008 by Regents of the University of Colorado.
Integrated Teaching and Learning Program, College of Engineering, University of Colorado Boulder
Last modified: February 26, 2015