SAY CAN YOU SEE
GRADE: 9 to 10
SUBJECT MATTER: Life Sciences: senses, The eye
TIME ALLOTMENT: Three 70 minute periods
STANDARDNational Science Education Standards http://www.nap.edu/readingroom/books/nses/html
PREP FOR TEACHER
For an average class of 24:
This site will enhance
your experience of dissecting the eye. http://www.exploratorium.edu/
This is a very thorough
site about the eye designed by students. http://library.thinkquest.org/C001464/
This site has an eye
tutorial which includes a section on diseases. http://numedsun.ncl.ac.uk
This site lets you
see the world through the eyes of a bee. http://cvs.anu.edu.au/andy/
Guided Imagery Have everyone close their eyes and completely relax (turn off lights). Tell them to imagine the most beautiful place they have been. Think of the lights, the brilliant colors, the people present. Who is with you? What do they look like? What are they wearing? What are you doing there? Keep this image in your mind and open your eyes (turn lights on).
Step 1. With the previous image in your minds, how would you feel if you are no longer able to see? Why? Do you feel sad and/or angry? How does the eye work? Discuss students’ concepts of vision. The brain perceives light and images.
Explain what they will see on the video. Go over the FOCUS FOR MEDIA INTERACTION
The students will complete the FOCUS FOR MEDIA INTERACTION worksheet as they watch the video.
Start video presentation Eyewitness 304-Sight (30 minutes). PAUSE at the eagle. Answer the worksheet. Check for understanding and answer any questions. START Continue until the discussion ends about “Take light in”. PAUSE
Complete the vocabulary definitions on worksheet. Look at the next questions so the students can look for the information needed to answer them. START and watch until just after the fly. PAUSE Discuss the compound eye. Fill in the worksheet. START . PAUSE after the blue glasses. Discuss how the color of an object is determined.
CONTINUE until after you see the camels in the desert. PAUSE Discuss the mirage. CONTINUE until the end. Complete the worksheet.
Step 2. Discuss
the following: What are the parts of the eye? Use overhead diagram and
have students look at their neighbors’ eyes. (Cornea, Lens, Pupil, Iris,
Retina, Optic nerve) What makes each part important? How does each function
help us see? Have students discuss what they think the function is. (leave
Have students turn to their neighbor at their table. Have them take turns closing and covering their eyes for 30 seconds and have their neighbor observe their pupil size change. Ask the students “Given what we have discussed, why does your pupil change?”
To adjust the amount of light entering the eye, give each student a piece of paper with a cross and a dot on it. Have each student close one eye and focus on the dot with the other eye (the cross should be to the outside of the face). Slowly bring the paper closer to them and notice how the cross will disappear. This is the blind spot. What causes a blind spot? It's the point where the optic nerve leaves the eye.
Ask the students “How come we don’t notice our blind spot on a daily basis?” The answer: We have two eyes and one compensates for the others blind spot. Ask the students “Now that you know how light is passed through the eye, how does your brain perceive colors and images?” (use transparency of rods and cones, brain)
Step 3. What is perception? Why do people perceive the same things differently? Sight is an amazing ability. Why, then, are some people without sight? What causes blindness? (Corneal diseases, Glaucoma, Albinism, Cataracts, Retinal diseases, Optic nerve damage, and Brain damage. Other eye conditions are Microphthalmia, Anophthalmia, Corticle visual impairment, and Coloboma.. Additional disabilities include Cerebral palsy, Cornelia de Lange Syndrome, CHARGE Syndrome, Mitochondrial disease, and Septo-Optic Dysplasia.)
Tell the students that “I have each of these causes in a hat. I will walk around the room and I want each student to choose one and write a 1-2 page paper on this cause of blindness.” They should have three days to do this. Tell them to be sure to answer the questions: How does it cause blindness? What part of the eye is affected?
POST VIEWING ACTIVITIES
STUDENT ASSESSMENT Students will be tested over the material covered in class. Identification of eye parts on a diagram. Teacher will label parts of an eye with numbered pins. Students will identify the part orally or on paper. Identification of cow eye parts. Ability to describe the function of they eye and all of its parts. Ability to describe the functions of the rods and cones. The research paper.
For additional lesson plans and ideas relating to this topic and many others try TeacherSource at PBS Online! You will find activities, lesson plans, teacher guides and links to other great educational web sites! Search the database by keyword, grade level or subject area! Mathline and Scienceline are also great resources for teachers seeking teaching tips, lesson plans, assessment methods, professional development, and much more!
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