Background: Helping upper elementary and lower secondary school students develop an awareness of various aspects of the nature of science (NOS) and nature of technology (NOT) is a widely recognized goal of science teaching. In this study, we focus on the connections between science and technology (S&T). Purpose: We report on the design, development, enactment and evaluation of a teaching-learning sequence (TLS) that combines hands-on activities in geometrical optics with explicit epistemological discourse for reflection purposes. The design of the TLS draws on perspectives from the inquiry-oriented and design-based teaching and learning frameworks. Sample: The enactment of the TLS involved a class of 17 sixth-grade students, aged 10-11 years old, of a public elementary school in Cyprus. Design and methods: We present findings from written responses to both closed and open-ended tasks as well as follow-up semi-structured interviews that probed students' understanding of the difference between the main goals of S&T. Results: The results illustrate elementary students' readiness to engage with epistemic issues and demonstrate the potential of prompting young learners' ability to develop informed awareness of the NOS and NOT. The results also provided feedback for the revision of the TLS so as to further enhance its effectiveness in achieving the stated learning objectives. Conclusion: We discuss the implications of our findings for the teaching of the NOS and NOT and for the design and validation of TLSs. It is possible for students of this age group to develop an awareness of issues related to the NOS and NOT. TLSs can be improved through design-based research approaches to serve as productive tools to this end.