Lesson plan: All eyes on laser surgery

September 25, 2000
Web posted at: 5:31 PM EDT (2131 GMT)

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Objectives

Students will be able to:

• Identify different methods for improving vision.
• Develop an alternative method for improving vision.

Standards

National Science Education Standards
Science and Technology, Content standard E, grades nine-12

High school students should know that science often advances with the introduction of new technologies. Solving technological problems may result in new scientific knowledge. New technologies often extend the current levels of scientific understanding and introduce new areas of research.

Benchmarks Online
The Nature of Technology, Issues in Technology, grades nine-12

High school students should know when deciding on proposals to introduce new technologies or to curtail existing ones. Some key questions arise concerning alternatives, risks, costs and benefits.

One class period

Materials

CNNfyi.com article, "An eye to the future"
Internet access
3-by-5 index cards
Measuring tape

Procedures

1. Discuss the human eye. Ask students the following:

• Why do think some people see better than others? Why do you think people's vision gets worse as they age?
• What are some ways that you have heard about to correct vision?

2. Have students read the CNNfyi.com article "An eye to the future." Then ask:

• Why do people have laser eye surgery?
• What are some comparisons and differences in radial keratectomy and photorefractive keratectomy?
• What is Lasik eye surgery? Describe how Lasik eye surgery works.
• What are some factors that make one a good candidate for Lasik eye surgery?
• What are some ways to preserve healthy eyesight?

3. Divide students into groups of four. Have each group write "cornea" in 2-centimeter-tall letters on an index card and "iris" in 2-centimeter-tall letters on another card. Students will test their vision by covering the left eye while looking at the word "cornea" on the index card held up by another student. The student holding the index card will back up until the student looking says "stop" once the image becomes blurry. Another student then will measure the distance from the eye to the index card. Repeat this procedure with all the students in the group. Students will then find the average distance with the right eye by repeating the procedure with students covering the right eye and using the card with the word "iris" printed on it.

4. Have each student develop a method to improve vision. Students may adapt a procedure discussed in the article.

Assessment

Write the data collected from each group on the board. Ask students:

• Do you think the procedures developed would benefit the class? Explain your answer.
• What do you think are the best actions to take to maintain and/or improve one's eyesight?

Accommodations

Visual/spatial: Students can draw diagrams of the human eye and label each part.

Challenge

Have students research stereoscopic or 3-D vision. Then have them write brief essays discussing how 3-D vision works. Students may also want to research the vision of animals. Do all animals that see have two eyes? Why are some animals' eyes on the sides of their heads rather than in the front?

Lasik Institute
American Academy of Ophthalmology
Visual Healing Alternative Medical Center
3-D Imagery -- Perception of the Human Eye
Human eye

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