Light-based sensing technologies have enabled and improved wide range of use cases. This presentation explores the foundational technologies, working principles and building blocks of light-based sensing and actuating. The focus is on specific use case values coming from consumer applications. Key technologies include specialization for light sensing of semiconductor, package, and system architecture including software. Complementing and competing technologies, such as radar and ultrasonic are also discussed. The presentation concludes with a call for industry collaboration to unleash the value of light- sensing in attractive verticals.