274 Introduction to Anatomy & Physiology 10. Predict the outcome of a student’s ability to do schoolwork without access to medical care for each of the following vision disorders: astigmatism, amblyopia, diplopia, strabismus, and hyperopia. 11. Research the different types of colorblindness and the impact it can have on the following activities of daily living: getting dressed, buying fruits and vegetables, cooking, driving, and spending a day at the beach. Present your findings to the class. 12. Another way of looking at the anatomy of the eye is to divide the eyeball into tunics. Conduct research to find the names of the three tunics of the eye and which structures each tunic includes. 13. Make a KWL chart like the one in Figure 7.11. Fill in the chart, listing what you know about accommodation, what you want to know, and, after doing the demonstration below, what you learned. K W L What I Know What I Want to Know What I Learned Figure 7.11 Goodheart-Willcox Publisher Demonstration: Close one eye and stare at a point about 20 feet away. The point at which you are staring should be in focus. While concentrating on the point, raise one of your fingers into your line of sight just below the point. Your finger should be a bit blurred. Now, change focus—look at the tip of your finger instead of the point 20 feet away. Your finger will come into focus, but the distant point will be blurred. 14. With a partner, obtain a Snellen chart and instructions for using it to assess visual acuity. Also obtain two index cards or other thin, opaque material to be used to cover the eyes. One student acts as the eye examiner and records the other student’s responses. Then switch roles so that each student has an opportunity to use the Snellen chart. Record your results. IN THE LAB optic tracts the continuation of the optic nerve fibers beyond the optic chiasma pupil the opening through which light rays enter the eye retina the innermost layer of the eye, containing light- sensitive nerve endings that send impulses through the optic nerves to the brain rods sensory cells in the retina that are activated in dim light sclera the tough, fibrous outer layer of the eye suspensory ligaments tiny structures that attach the lens of the eye to the ciliary body tarsal glands secretors of an oily substance located in the eyelids vitreous humor gel-like substance that fills the posterior chamber of the eye contributes to intraocular pressure Know and Understand 1. List the anatomical features that protect the eye from injury. 2. Which glands produce the salty solution known as tears? 3. Where are the extrinsic muscles and what is their purpose? 4. What part of the eye is called the “window of the eye?” 5. Rods and cones are located in which layer of the eye? 6. Describe the pathway of vision. 7. What part of the eye has many pain receptors and is able to repair itself quickly? Analyze and Apply 8. Compare and contrast myopia, hyperopia, and presbyopia. 9. Derrick has had to do a lot of reading in college. He never had a problem with his vision in the past, but lately he has had trouble reading the print in his textbook. When he noticed that he was holding his book farther and farther away from his eyes, he decided to see an ophthalmologist. What do you think the doctor told Derrick? Which injury, disorder, or disease that you read about in this chapter was the diagnosis? What treatment do you think the doctor prescribed? Copyright Goodheart-Willcox Co., Inc.