Wearable Health Technologies are becoming an integrated part of various consumer devices like smartwatches, fitness trackers, smart-rings, etc. Each device has an array of sensors to monitor vital parameters for health and fitness monitoring. The talk will provide an overview of the critical components of wearable health technology and the role of optical sensors in monitoring various vital parameters in wearable health devices. The application of optical sensors to monitor SpO2, respiratory rate, heart rate variability, and non-invasive glucose monitoring will be discussed.