The purpose of this CPD is to try to explain why lighting is so important not just to a physical space but to us as humans. We investigate why a warmer light makes a room feel cozier and why a cooler one makes us more alert and able to concentrate. We look at how our bodies are preprogrammed to work in this why and how this can be aided from a lighting perspective. By the end of this CPD delegates should: 1. Understand the history of light and where artificial light fits into this. 2. Understand the structure of the eye, how different people see the world differently, how and why the quality light matters and how this is measured. 3. Understand how our bodies are programmed to respond to different colour temperatures of light and how we can support this in a home environment using tuneable light sources. 4. Understand the seven principles of biophilic design and how lighting can play its part. 5. Understand commonly asked questions relating to LEDs and tuneable light sources.