In recent times, wearables internet of things (IoT) devices has gained popularity due to their ability to improve many facets of our daily lives. This innovative technology is equipped with sensors, processors, and other electronic components to collect and transmit data to the cloud for processing important insights. However, the limited power supply, frequent recharging, and user inconvenience, are some of the critical barriers to their widespread adoption. To circumvent these constraints, effective energy harvesters are essential. This paper proposes light energy harvesting to power up wearable IoT devices. It consists of a small photovoltaic (PV) panel, energy management IC and lithium polymer (LiPo) rechargeable battery. The experiments include a baseline system, LiPo charging and discharging, and the light energy harvesting system under natural sunlight. Experimental results show that the light energy harvesting enabled wearable IoT system can provide an increase in lifetime of more than 300 when compared to the baseline system. This shows that light energy harvesting is a reliable and efficient option to power a wearable IoT device, making it a promising option for self-powered, and sustainable wearables IoT. © 2023 IEEE.