HEALTHY VISION SEEING IS BELIEVING

Transcription

1 THE EYEBALL HOW THE EYE WORKS HEALTH AND SAFETY EYE DISEASES & DISORDERS EYE-XPLORATION EXERCISE YOUR EYES HOW THE EYE USES LIGHT OPHTHALMOLOGICAL TECHNOLOGY HEALTHY VISION SEEING IS BELIEVING HIGH SCHOOL Curriculum and Instruction Division of Mathematics, Science, and Advanced Academic Programs

2 THE SCHOOL BOARD OF MIAMI-DADE COUNTY, FLORIDA Perla Tabares Hantman, Chair Dr. Lawrence S. Feldman, Vice Chair Dr. Dorothy Bendross-Mindingall Carlos L. Curbelo Renier Diaz de la Portilla Dr. Wilbert Tee Holloway Dr. Martin Karp Dr. Marta Pérez Raquel A. Regalado Hope Wilcox Student Advisor Mr. Alberto M. Carvalho Superintendent of Schools Ms. Milagros R. Fornell Associate Superintendent Curriculum and Instruction Dr. Maria P. de Armas Assistant Superintendent Curriculum and Instruction, K-12 Core Mrs. Beatriz Zarraluqui Administrative Director Division of Mathematics, Science, and Advanced Academic Program

3 Dear Teacher, May is Healthy Vision Month, a national eye health observance established by the National Eye Institute (NEI) in May NEI is one of the National Institutes of Health, an agency of the U.S. Department of Health and Human Services. Healthy Vision Month is designed to promote vision as a health priority for the nation. Millions of people living in the United States have undetected vision problems, eye diseases, and conditions. Miami-Dade County Public Schools is committed to educating our students and teachers on the use of preventive care to avoid eye diseases and disorders and to preserve sight. Information about the latest technologies used to correct vision problems and to see way off into space is also included! The Division of Mathematics, Science, and Advanced Academic Programs is providing you with a packet that contains activities to use with your students during the month of May to educate students about vision care. A list of websites is included to provide additional resources to complement or supplement classroom activities. Please visit the Science department website to download the packet, 1

4 TABLE OF CONTENTS Light: All Those Seeing Color, Say Eye! 5 SC.912.P Explore the theory of electromagnetism by comparing and contrasting the different parts of the electromagnetic spectrum in terms of wavelength, frequency, and energy, and relate them to phenomena and applications. SC.912.P Explain that all objects emit and absorb electromagnetic radiation and distinguish between objects that are blackbody radiators and those that are not. A-Z Diseases and Disorders 10 SC.912.N.1.7 Recognize the role of creativity in constructing scientific questions, methods, and explanations. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspective of both individual and public health. History of Remote Sensing..11 SC.912.E.5.7 Relate the history of and explain the justification for future space exploration and continuing technology development. SC.912.E.5.8 Connect the concepts of radiation and the electromagnetic spectrum to the use of historical and newly-developed observational tools. SC.912.P Qualitatively describe the shift in frequency in sound or electromagnetic waves due to the relative motion of a source or a receiver. Remote Sensing Exploration...15 SC.912.N.1.6 Describe how scientific inferences are drawn from scientific observations and provide examples from the content being studied. SC.912.P Describe the measurable properties of waves and explain the relationships among them and how these properties change when the wave moves from one medium to another. Preserving the Miracle of Sight: Lasers and Eye Surgery...19 SC.912.N.1.6 Describe how scientific inferences are drawn from scientific observations and provide examples from the content being studied. SC.912.P Explain that all objects emit and absorb electromagnetic radiation and distinguish between objects that are blackbody radiators and those that are not. SC.912.P Construct ray diagrams and use thin lens and mirror equations to locate the images formed by lenses and mirrors. References

5 Light: All Those Seeing Color, Say Eye! Adapted from Science Net Links NGSSS Benchmarks SC.912.P Explore the theory of electromagnetism by comparing and contrasting the different parts of the electromagnetic spectrum in terms of wavelength, frequency, and energy, and relate them to phenomena and applications. SC.912.P Explain that all objects emit and absorb electromagnetic radiation and distinguish between objects that are blackbody radiators and those that are not. Objective To introduce the roles of the eye and brain in the perception of objects, including color. Background Many students do not think of light as something that travels from one place to another, and most tend to identify light with its source (e.g., light is in the bulb) or its effects (e.g., a patch of light). As a result, students have difficulty explaining the direction and formation of shadows, as well as reflection of light by objects. Students usually understand that mirrors reflect light, but have a hard time believing that of objects which do not reflect their image. Many students do not believe that their eyes actually receive light when looking at an object. Students' ideas of vision vary from the notion that light fills space and the eye sees without anything linking it to the object, to the idea that light illuminates surfaces that we can see by the action of our eyes upon them. The notion that the eye can see without a link to the object is a notion that can even persist after basic instruction in optics. This lesson is an introduction to light, preparing students to address issues like those discussed above. This lesson introduces students to the electromagnetic spectrum (focusing on visible light) and the wave nature of light. This lesson focuses on the idea that we can see objects because they either emit or reflect light. It discusses the way light is reflected, absorbed, and scattered to allow certain wavelengths to reach the eye, leading to a perception of different colors. This lesson includes an Internet exploration that focuses on the roles of the eye and brain in the perception of color. It includes an introduction to the anatomy of the eye, including the functions of rods and cones. Materials: All Those Seeing Color, Say Eye! student sheet Motivation Ask the following questions to generate student interest in this lesson, as well as review basic concepts: 3

6 What are some "sources" of light? (Examples include the sun, fluorescent lights, and incandescent bulbs.) Have you ever noticed that objects look different colors in different light? (For example, a fluorescent bulb produces a bluish colored light while an incandescent bulb produces reddish light.) In what ways can light be reflected when it hits a surface? (If the surface is smooth, the light is reflected at the same angle it came in. If the surface is rough, the light is scattered in all directions. When the surface is somewhere inbetween, it reflects light close to the same angle it came in.) Is anyone colorblind? If you have ever watched the sun set, you may have noticed that as it gets darker, it becomes more difficult to distinguish the colors of the objects around you. What might cause the colors to be less distinct? (As there is less light from the sun, less light is reflected from the surfaces around you. Therefore, your eyes are less able to distinguish color.) Development In this section, students will read information online. Go to An Eye on Color slideshow ( and answer questions on the student sheet, All Those Seeing Color, Say Eye! Depending on the number of available computers, students could work alone or in small groups. Distribute the student sheet and have students complete Part I. As outlined on the student sheet, students will view a slideshow, An Eye on Color, from The Tech Museum of Innovation, and answer questions. After students finish, discuss the questions listed on the student sheet in class: What happens when waves of light enter your eye? Discuss the role of the pupil, retina, and optic nerve. (Light comes in through the pupil and splashes inside your eye on the retina. Optic nerves carry information about the light to your brain.) Where are rods and cones located? (Retina.) What are rods and cones? What do they allow you to see? (Rods let you see black and white only; cones let you see color.) In what area of the retina are cones concentrated? (Center.) When do cones work best? (When there's a lot of light, like during the day.) In what area of the retina are rods concentrated? (Edge.) When do rods work best? (In dim light, like late in the evening.) You've just read what happens in the eye: light goes through the pupil, then hits the rods and cones and causes a chemical reaction. What understands this reaction and carries the message to the brain? (Optic nerve.) What causes the blind spot? (You don't have rods or cones where the optic nerve connects to your retina; there you have a blind spot. You can't see light that hits your blind spot.) Why do certain animals (like the owl and bee) see colors differently than humans? (They have different cones.) 4

7 Now have students complete Part II on the student sheet. Go to A Big Look at the Eye on the KidsHealth website at This requires students to continue their exploration of the eye, light, and color. They'll read in more detail about the anatomy of the eye, optic nerve, and how messages are transmitted to the brain. When they are finished, discuss the questions on the student sheet in class: What are functions of the eyelid and blinking? (Blinking allows the eyelid to help keep the eye clean.) What is a function of eyelashes? (Eyelashes work with the eyelid to keep dirt and other stuff out of the eye.) Draw a diagram of the eye labeling the sclera, cornea, iris, and pupil. What part of the eye lets light in? (Pupil.) What happens to the pupil as you enter a dark room? Why? (It gets larger, in order to let more light in.) Once light enters through the pupil, what part of the eye focuses light on the retina? (Lens.) What carries messages from the eye to the brain? (Optic nerve.) Assessment Use the student sheets and class discussions to assess student understanding. In addition, have students draw a diagram illustrating the movement of light from outside the eye, into the eye, and finally to the brain. Have students label at least the following in their diagrams: light source, object that is seen, pupil, lens, retina, rods, cones, optic nerve, and brain. 5

8 All Those Seeing Color, Say Eye! Student Worksheet Name: Part I Go to An Eye on Color slideshow ( on the Tech Museum of Innovation website. First, click on the link titled Inside Your Eyeball. Then navigate through the slideshow by clicking on the link within the text of each slide. Stop when the slideshow is over. As you read the slides, answer the following questions: 1. What happens when waves of light enter your eye? 2. Discuss the role of the pupil, retina, and optic nerve. 3. Where are rods and cones located? 4. What are rods and cones? What do they allow you to see? 5. In what area of the retina are cones concentrated? 6. When do cones work best? 7. In what area of the retina are rods concentrated? 8. When do rods work best? 9. You ve just read what happens in the eye: light goes through the pupil, then hits the rods and cones and causes a chemical reaction. What understands this reaction and carries the message to the brain? 10. What causes the blind spot? 11. Why do certain animals (like the owl and bee) see colors differently than humans? Part II Go to A Big Look at the Eye on the KidsHealth website. Navigate through the article by clicking on the Next Page link at the bottom of each slide. After you read the The Eyes Take the Prize page, click on the link Want to see the eye in action? Then click on The Eye. As you read the article, answer the following questions: 1. What are functions of the eyelid and blinking? 2. What is a function of eyelashes? 3. Draw a diagram of the eye labeling the sclera, cornea, iris, and pupil. 4. What part of the eye lets light in? 5. What happens to the pupil as you enter a dark room? Why? 6. Once light enters through the pupil, what part of the eye focuses light on the retina? 7. What carries messages from the eye to the brain? 6

9 A-Z Diseases and Disorders Adapted from National Eye Institute NGSSS Benchmarks SC.912.N.1.7 Recognize the role of creativity in constructing scientific questions, methods, and explanations. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspective of both individual and public health. Visit the National Eye Institute to research eye diseases and disorders at: 1. Create a chart of 7 eye diseases or disorders using the categories below. Report the information to your classmates using a presentation style of your choice. Cause of Disease/ Disorder (including genetic factors, environmental factors, and pathogenic agents) Parts of the eye impacted Who is at risk? Symptoms Treatment options 2. Interview an optometrist or ophthalmologist. Work with the practitioner to conduct a project that requires specifying a problem related to an eye disease/ disorder, design an experiment, analyze data, and report results and implications. 3. Write a letter to your legislator outlining the causes and effects of three eye diseases/ disorders. Make a convincing argument for national eye care. 4. Create flowcharts/charts/timelines on scientific discoveries related to eye diseases/ disorders. 5. Make an informational booklet of eye diseases/ disorders. Be sure to include causes of diseases/ disorders, parts of the eye impacted, who is at risk, symptoms, and treatment options. 6. Create an informational TV commercial on the importance of healthy eye care. Make references to several eye diseases and disorders to support your commercial. 7

10 History of Remote Sensing Adapted from Science NetLinks NGSSS Benchmarks SC.912.N.1.7 Recognize the role of creativity in constructing scientific questions, methods, and explanations. SC.912.L.14.6 Explain the significance of genetic factors, environmental factors, and pathogenic agents to health from the perspective of both individual and public health. Objective To identify a historical example of how advances in science depend on advances in technology and vice versa. After studying the article, students should be able to: Define remote sensing. Explain how remote sensing developed. Tell what motivated people to look at the Earth from a different perspective. Explain how the process of obtaining remotely sensed information evolved from aerial photography to satellite imagery. Background In this lesson, students will focus on the history of remote sensing which, when tied to human history, has profoundly changed the way we view and understand our world. Students will read an online article that details the early uses of remote sensing. The article also shows how remote sensing technologies have advanced, from early telescopes to satellites, and what possibilities exist for future applications. Students will also participate in an activity that allows them to pretend they are part of a remote sensing satellite. Motivation Begin this lesson by asking students the following questions: Have you ever heard of remote sensing? What is remote sensing? When do you think remote sensing technology developed? What are some reasons as to why people might have wanted to develop and advance remote sensing techniques? Some students may have some ideas about this, but it doesn't matter at this point if their understanding of remote sensing is correct or complete. After students read the article and answer questions, they should then be able to define remote sensing and how it developed as a technology to enhance scientific understanding. 8

11 History of Remote Sensing 2.html Additional resource: Distribute copies of the student sheet Remote Sensing. Tell students that they will read a short online resource about remote sensing ( and answer questions on the worksheet. Students can do this activity as homework or in a school computer lab during class time. Ask students: How is remote sensing technology important to scientific understanding of the world? Why do you think scientific questions about the world lead to the development of technologies such as telescopes, hot air balloons, and satellites? How is remote sensing a good example of how technology and science work together to solve problems? Point out to students that developing these types of technology required scientific understanding. For example, making a telescope required the understanding of optics how we see and magnification techniques. Hot air ballooning depended upon the science of chemistry and behavior of gases in conditions of varying temperature and pressure. Developing satellites required immense knowledge of forces such as gravity, friction, and motion, as well as materials science (engineering the satellite, wiring, and construction). Thus, while each of these technologies contributed to our knowledge of remote sensing, the development of these technologies required research and experimentation in other fields of science. When students have completed the student sheet, they should share their answers with the whole class. Assessment To assess student understanding of the concepts covered in this lesson, ask the following questions: Technology is sometimes perceived as being "bad," leading to the development of tools that are destructive to humans and the Earth. How would you respond to such a statement? Why are tools important to the development of science? What are some important scientific questions facing the world today? How will technology help to solve these questions? 9

12 Name: History of Remote Sensing Student Worksheet Read the online article Remote Sensing in History and answer the following questions. Remote Sensing in History 2.html 1. What is remote sensing? 2. Why would people want to detect, observe, or sense something from great distances? 3. When where the first aerial photographs taken? Describe some drawbacks involved in these early attempts. 4. How did the use of airplanes help armies gather information in World Wars I and II? How well did this work? 5. How did space flight change the nature of remote sensing? Why was better technology needed to help us get images of the earth from space? 6. Describe four examples of how remote sensing imagery was used in the 1980 s. 7. Describe three examples of how remote sensing imagery was used in the 1990 s. 10

13 Remote Sensing Exploration Adapted from Science NetLinks NGSSS Benchmarks SC.912.N.1.6 Describe how scientific inferences are drawn from scientific observations and provide examples from the content being studied. SC.912.P Describe the measurable properties of waves and explain the relationships among them and how these properties change when the wave moves from one medium to another. Objective This activity will allow students to pretend they are part of a remote sensing satellite. The purpose is to help them understand why sensors of different wavelengths can only see certain colors and why they can only produce certain colors on photos. Background The history of remote sensing, which, when tied to human history, has profoundly changed the way we view and understand our world. It details the early uses of remote sensing, from Galileo in 1609 to the Mississippi River flooding of It reinforces the notion of the intelligence and insight of our forefathers. Similarly, it will show how remote sensing technologies have advanced, from early telescopes to satellites, and what possibilities exist for future applications. Aerial photography and satellites are used for military and commercial applications. Remote sensing has evolved greatly since the days of Galileo. The transition from analog data to digital data has created an explosion in the amount of information obtained from remote sensing platforms. Satellites were first used during the Cold War. Today they are used by many disciplines, from geography to agronomy. There is a great demand for the commercial application of this once classified data source. Classroom Activities Be Part of a Remote Sensing Satellite Prior to this activity, there should be an introduction to remote sensing, color, and light. Discuss the basic parts of a remote sensing satellite, such as the platform, the sensors, and the filters. Students should have some basic understanding of the color wheel, too. It would be a good idea to show them some examples of different types of remotely sensed images (true color, infrared, etc.). This will let them see that color can vary from image to image. These images will also help students to understand the perspective of viewing the Earth from above. Materials: 1. One set of "glasses" for each student (red, blue, or green, depending on which group they are in; see directions below) 2. Red, blue, and green pipe cleaners (enough to distribute several to each student) sheets of green, blue, and red acetate (or overhead projector sheets) 11

14 Prior to Activity Directions for making "glasses": 1. Cut out pieces of the acetate large enough to cover the students' eyes. 2. Give each student a different color of the acetate to use as lenses in the "glasses." 3. Spread out the pipe cleaners on a grassy area outside; they should not be hidden. Procedure 1. Divide the students into three equal groups; one group for red "glasses," one for blue, and one for green. 2. Pass out the "glasses" before going outside. Be sure the students cover their eyes with the colored "glasses" before they near the area where the pipe cleaners are located. 3. Explain the situation and the rules to the students. a. The students will pretend they are the sensors of satellites and, as satellites do, they will search for things that they can see through their colored "glasses." b. Students can only look through their "glasses" to find the pipe cleaners. c. When a student sees a pipe cleaner, he or she will pick it up. d. When the time limit (10-15 minutes) is reached, have the students look to see what everyone picked up. (You could have the students trade colors to see what happens when looking through different colored "glasses.") e. Have a discussion about why students were only able to see certain colors through their "glasses." Assessment Q: What is remote sensing? A: Remote sensing is the science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation. It is a process of obtaining information without coming into direct contact with the object being observed. Q: Why use remote sensing for obtaining information about areas or objects? A: Remote sensing permits researchers to "read" the Earth. The US space program stresses that the fundamental goal of remote sensing is to advance scientific knowledge of the Earth and its environment so as to understand and eventually predict both natural and human-induced global change and, thus, provide continuing benefits to humanity. Q: What types of satellites are used for remote sensing of the Earth? A: There are many types of satellites used for remote sensing of the Earth. The three major types are meteorological, oceanographic, and terrestrial satellites. Meteorological satellites are used to obtain information about the Earth's weather. The data obtained from these satellites are entered into a computer to create a forecast model. Oceanographic satellites obtain data about the Earth's oceans and other water bodies to help us understand the oceanic system of tides, water temperatures, etc. The usefulness of these satellites is demonstrated in the predictions that were made for this 12

15 year's climatic phenomenon known as El Niño. Terrestrial satellites obtain data about the Earth's land surface. The range of the electromagnetic spectrum allows researchers to see the Earth from a different perspective. These data are useful in predicting crop yields for agriculture and aiding cartographers in map making. Vocabulary Galileo: ( ) Italian astronomer and physicist. Through his spyglass, Galileo made careful observations and measurements of the universe. His most stunning (and controversial!) discovery was of satellites orbiting Jupiter, dashing the concept of an Earth-centered universe with all objects revolving around the Earth. photography: the process of producing images on a sensitized surface by the action of light or other radiant energy. photo interpretation: the process of examining aerial photographs and images for the purpose of identifying objects and judging their significance. photoreconnaissance: a survey of a region performed with an aerial photography platform (e.g., balloon, pigeon, airplane). reconnaissance: a survey of a region for the purpose of ascertaining the locations of objects. 13

16 Preserving the Miracle of Sight: Lasers and Eye Surgery Adapted from the National Eye Institute NGSS Benchmarks SC.912.N.1.6 Describe how scientific inferences are drawn from scientific observations and provide examples from the content being studied. SC.912.P Explain that all objects emit and absorb electromagnetic radiation and distinguish between objects that are blackbody radiators and those that are not. SC.912.P Construct ray diagrams and use thin lens and mirror equations to locate the images formed by lenses and mirrors. This article tells the story of how medical research into the structure of the eye and research in physics on light and met to benefit diabetes patients and others with eye problems. Researchers have studied the structure of the human eye since the 1600s and came to understand it fairly well by the 1900s. Sudden retinal detachments remained a puzzle until 1918 when an ophthalmologist came to understand how the vitreous fluid in the eye played a vital role in this process. Meanwhile, physicists such as Albert Einstein were studying the nature of light and discovered that atoms can absorb energy and emit it later at specific frequencies. They also discovered that under the right conditions, they can trigger a chain reaction of this type of emission, which is the basic principle behind lasers. As ophthalmologists continued research to perfect techniques to seal retinal tears, they realized that bright beams of light at some wavelengths could be used for this procedure. The first such device used a high-pressure xenon arc lamp. At the same time, scientists were studying microwave radar and invented the device known as a maser. This was the precursor for the laser, and by 1960 they had built a laser device using a synthetic ruby. The ruby laser was used very successfully to repair some retinal problems, but not all. Scientists realized that they needed light of higher frequency for treating diabetic retinal problems. Collaborations between medical doctors and physicists led to the development of the Argon laser used for this purpose. Recently, lasers have been used in the lasik type operations which allow doctors to reshape a person s cornea to correct vision problems. Ophthalmologists continue to explore exciting new possibilities for using lasers in medicine. Laser Technology Applied Diabetic retinopathy, a dangerous complication of diabetes, is the leading cause of new cases of blindness among adults. An estimated 12,000 to 24,000 diabetics lose their sight each year in the United States to this insidious disorder--largely because they do not receive the regular eye exams that could catch the problem early. When caught in time the damaging changes in retinal blood vessels brought on by diabetes can be stopped--and in some cases even reversed--using the powerful, tightly focused beam of a laser. Timely laser intervention can prevent blindness in up to 90 percent of such cases. 14

17 Precision lasers also can repair small tears in the retina that might otherwise lead to retinal detachment, and they are used in surgery related to cataracts, although, contrary to popular belief, they are not used for the removal of cataracts themselves. Doctors recently have begun using lasers in a procedure called photorefractive keratectomy, or PRK, to "sculpt" the surface of the cornea--the eye's clear protective covering--to correct nearsightedness. All of these procedures can be done in a matter of minutes, with relatively little pain or discomfort. The article describes how two streams of basic research--one in human anatomy and medicine, the other in physics --intersected in the early 1960s to produce a revolution in ophthalmology that has saved hundreds of thousands of people from severe vision impairment or blindness. As is so often the case in science, many of those who made the landmark discoveries were motivated primarily by the desire simply to understand nature--but their efforts paved the way for a host of unexpected practical results. Diabetes ran in Bill's family: both of his paternal great-grandparents and his paternal grandfather developed diabetes as adults. For Bill the onset of the disease occurred before he was 3 years old. At the age of 8, he took over administering his own insulin shots, beginning a lifetime of strict adherence to a routine vital to his health. This discipline probably delayed the onset of diabetic retinopathy, the insidious and visionthreatening complication that affects nearly all patients with younger-onset diabetes, by the age of 15 or 20. Bill didn't have vision problems until he was about 30, and because he had regular eye exams, doctors caught it early. Laser photocoagulation--making a number of small laser burns around the periphery of the retina--sealed off the abnormal blood vessel growth that can lead to blindness if left untreated. In 1992 Bill had the surgery on both eyes, a procedure that can be done in a doctor's office simply by beaming laser light through the dilated pupil. "I go in four times a year now," Bill reported a few years later, adding that his doctors are very pleased with the results. In the fall of 1997, a 57-year-old entrepreneur named John woke up one morning seeing flashes of light and spots, or floaters, in front of his eyes. When they persisted the next day, he went to an ophthalmologist, who diagnosed the problem as posterior vitreous detachment and a small retinal tear. The vitreous, a clear, jelly-like fluid that fills the inside of the eye, tends to degenerate during middle age, shrinking and pulling away from the retina. This detachment is common in nearsighted people; John had worn glasses for nearsightedness since the age of 13. Occasionally, the retina is torn when the vitreous pulls away, causing a small amount of bleeding that appears as a sudden onset of floaters. To prevent the tear in John's retina from developing into a retinal detachment, the doctor used a laser to seal it--in effect, spot welding the tear. The procedure took only minutes. The ease and brevity of these two operations underscore the revolution that lasers have brought to the field of eye care. As recently as the 1950s, almost any eye surgery required a patient to be bedridden for weeks. Today, thousands of people each year have their vision restored or sharpened in procedures that are often virtually painless, 15

18 owing to the laser's precision and the fact that it operates not with a blade but with a beam of light. By sending a focused laser beam through a patient's pupil, a surgeon can reach the interior of the eye without having to cut into the eye itself. The actual surgery causes little or no discomfort, there are no incisions to heal and no damage to other areas of the eye, and recovery time is minimal. For all their high-tech wizardry, the application of lasers and other modern surgical techniques in ophthalmology would not have come about were it not for the researchers who first painstakingly figured out how the eye works and identified the causes of various defects in vision. One long-held belief was that the lens, which lies just behind the pupil and helps to focus light on the retina, was the seat of vision and that removing it would result in blindness. The ancients had no notion of the retina and its crucial role. 16

19 Lasers Saving Sight Student Work Sheet Name: Directions: Read the article Preserving the Miracle of Sight. As you are reading, answer the following questions. 1. Trace the history of laser technology. 2. Name the two streams of research that contributed to the development of laser eye surgery. 3. How can diabetic patients prevent blindness? 4. What eye problems can be treated with laser surgery? 5. Describe how the retina works. Why is it so vulnerable? 6. Why was there a need to revolutionize the lasers used by ophthalmologists? 7. Compare the eye diseases and treatments of Bill and John in the article. 8. Draw conclusions about the development of research in physics on light and eye disorders. 9. Develop a logical argument for the use of lasers for diseases of other parts of the body. 10. Why is it important that scientists continue to do research and test their claims? 17

20 Healthy Vision Care Links Prevent Blindness America American Academy of Ophthalmology American Optometric Association National Safety Council 18

21 Federal and State Laws The School Board of Miami-Dade County, Florida adheres to a policy of nondiscrimination in employment and educational programs/activities and strives affirmatively to provide equal opportunity for all as required by law: Title VI of the Civil Rights Act of prohibits discrimination on the basis of race, color, religion, or national origin. Title VII of the Civil Rights Act of 1964, as amended - prohibits discrimination in employment on the basis of race, color, religion, gender, or national origin. Title IX of the Educational Amendments of prohibits discrimination on the basis of gender. Age Discrimination in Employment Act of 1967 (ADEA), as amended - prohibits discrimination on the basis of age with respect to individuals who are at least 40. The Equal Pay Act of 1963, as amended - prohibits gender discrimination in payment of wages to women and men performing substantially equal work in the same establishment. Section 504 of the Rehabilitation Act of prohibits discrimination against the disabled. Americans with Disabilities Act of 1990 (ADA) - prohibits discrimination against individuals with disabilities in employment, public service, public accommodations and telecommunications. The Family and Medical Leave Act of 1993 (FMLA) - requires covered employers to provide up to 12 weeks of unpaid, job-protected leave to eligible employees for certain family and medical reasons. The Pregnancy Discrimination Act of prohibits discrimination in employment on the basis of pregnancy, childbirth, or related medical conditions. Florida Educational Equity Act (FEEA) - prohibits discrimination on the basis of race, gender, national origin, marital status, or handicap against a student or employee. Florida Civil Rights Act of secures for all individuals within the state freedom from discrimination because of race, color, religion, sex, national origin, age, handicap, or marital status. Veterans are provided re-employment rights in accordance with P.L (Federal Law) and Section (Florida Statutes), which stipulates categorical preferences for employment. Revised 9/