This study outlines ongoing research within the area of physics education, namely the investigation of the relationship between conceptual understanding and quantitative problem-solving. Industry, society and research need graduates to be excellent problem solvers with an ability to conceptualise and transfer their understanding and knowledge. However recent research has shown that physics students are not developing the conceptual understanding necessary to become adept problem-solvers. Physics education tends to rely on the assumption that students will develop an understanding of the conceptual nature of physics by solving quantitative problems. Research has shown that this is not the case and students cannot develop as problem-solvers without first having the conceptual understanding. Many of these physics graduates go on to work in optics, in areas such as nanotechnology, photonics fabrication and optical sensing. This research involves an investigation of student learning in physics and the impact this has on conceptual understanding and their ability to solve quantitative and qualitative problems. It builds on research carried out in the United States in order to obtain a better understanding of how students learn physics and the difficulties they have developing an understanding of the conceptual nature of physics. It aims to develop a systematic way of identifying students’ misconceptions in physics and to assess the affect these have on student learning and the development of understanding. This research will inform teaching and assessment practices, not only in physics education but also in other disciplines so that third level education can produce better problem-solvers for industry, research and a knowledge-based society.