In this service-learning engineering project, students follow the steps of the engineering design process to design a hearing testing device. More specifically, they design a prototype machine that can be used to test the peripheral vision of partially-blind, pre-verbal children. Students learn about the basics of vision and vision loss. They also learn how a peripheral vision tester for adults works (by testing the static peripheral vision in the four quadrants of the visual field with four controllable lights in specific locations). Then they modify the idea of the adult peripheral vision tester to make it usable for testing young children. The class designs and builds one complete prototype, working in sub-groups of four or five students each to build sub-components of the project design.

Students apply everything they have learned over the course of the associated lessons about waves, light properties, the electromagnetic spectrum, and the structure of the eye, by designing devices that can aid color blind people in distinguishing colors. Students learn about the engineering design process and develop three possible solutions to the engineering design challenge outlined in lesson 1 of this unit. They create posters to display their three design ideas and the comparisons used to select the best design. Then, students create brochures for their final design ideas, and "sell" the ideas to their "client." Through this activity, students complete the legacy cycle by "going public" with the creation of their informative posters and brochures that explain their designs, as well as color blindness and how people see color, in "client" presentations.

Students are presented with a challenge question concerning color blindness and asked to use engineering principles to design devices to help people who are color blind. Using the legacy cycle as a model, this unit is comprised of five lessons designed to teach wave properties, the electromagnetic spectrum, and the anatomy of the human eye in an interactive format that introduces engineering applications and real-world references. It culminates with an activity in which student teams apply what they have learned to design devices that can aid people with colorblindness in distinguishing colors— as evidenced by their creation of brainstorming posters, descriptive brochures and short team presentations, as if they were engineers reporting to clients. Through this unit, students become more aware of the connections between the biology of the eye and the physical science concept of light, and gain an understanding of how those scientific concepts relate to the field of engineering.

Students further their understanding of the engineering design process while combining mechanical engineering and bioengineering to create assistive devices. During this extended activity (seven class periods), students are given a fictional client statement and required to follow the steps of the engineering design process (EDP) to design a new wristwatch face for a visually impaired student at their school. Student groups share their designs with the class through design presentations. A successful design meets all of the student-generated design requirements, including the development of a new method of representing time that does not require the sense of sight. Through this activity, students design, construct and iterate classroom prototypes of their watch designs.