Exploring a Lens

Print Lesson


SWBAT create and use a model to develop an understanding of how a lens is used and connect this information to the lens of their eye.

Big Idea

To better understand how a part of our eye works, students will use water and plastic bag. These two tools will help use explore the way in which a lens works.

First Observations

10 minutes

To open this lesson I refer back to our science journal. We will need to use it anyway and they can begin by looking at their diagrams on the eye. I ask students to take note at where the lens of the eye is. Today we are going to explore the way in which a lens helps us to see and how it works. 

To begin, the class needs to observe their eye in a mirror. They will record the observations in their journal and try to see where the lens is as a part of their own eye. I allow groups of students to go to the bathroom to make this observation and come back to record. 

Outside Classroom and Observations

15 minutes

Students now have three-quarter filled bags of water and are ready to make some observations. As we work with the water, they will need to pour it out as they observe. We move our experiment outside so that they can pour without consequence. Students are placed in various locations and are first asked to to find something to be the center of their focus and observation. They will begin by recording what they see with their own eyes.

Next, students will use the bag of water as a lens to view their object. The first one is done with a bag filled with water. They will then draw what their object looks like through the water. They continue to do this pouring out a little water each time until they have nothing left.  

Completing Notes and Discussion

10 minutes

Once we have made all of our observations, students will go back inside to complete their notebook findings. They will need to write a conclusion to what they learned from their observations. As a class we then discuss how the lens of the eye was like our bag of water. We discuss how the curved or convex nature of the bag of water bends the light so that we can see.