Abstract: A ring-type wearable device is provided for sensing biometric data associated with various physiological conditions of the user. In one embodiment, a ring apparatus comprises a ring body including an opening formed therethrough structured to receive a body portion of a user therein when worn by the user; and an electronic computer processor programmed for processing one or more signals detected by the apparatus and associated with one or more biometrics associated with a physiological condition of the user into processed data. A light sensor system connected to the ring body includes multiple light-emitting diodes (LEDs), wherein each LED is associated with a predetermined light wavelength range, a first photodetector configured for light detection in a reflection mode, and a second photodetector configured for light detection in a transmission mode, each for detecting at least a portion of the light originating from the multiple LEDs.