Students learn about the eyelids, eyelashes, iris, sclera, and the pupil, and the function of each of these parts. Explain that the pupil responds to light by becoming smaller when light shines near it. Have students drag the flashlight onto the eye to shrink the pupil. After this, explain the other parts of the eye: the cornea, lens, anterior chamber, optic nerve, retina, and vitreous body. Describe each part and its purpose. Next, students learn how vision works. Light travels through the cornea and reaches the lens. The image is sent to the retina, and it is finally sent to the brain through the optic nerve where it is processed and translated into something we can understand and recognize. Discuss how our eyes can sometimes play tricks on us and explain how optical illusions work. Let students share from their own personal experiences and try to decipher an optical illusion on the interactive whiteboard. Finally, explain the function of tears and share some ways to protect your eyes.