A light emitter and light sensor pair can be used to determine one or more characteristics of a users vasculature. For example, a pulse oximeter employs a light emitter and a light sensor to measure the percentage of oxygenated blood in a subject. In examples of the present disclosure, light emitters and light Receive motion sensors can be used to perform biometric identification information of a user based on identifying characteristics of the users vasculature. For example, light information can be obtained at one or more light sensors, and the information information can be compared to stored information associated with a user identity. Based on the comparison, the user of the device can be identified as having the user identity.
