The disclosure describes artificial reality systems and techniques for providing artificial reality content to a user. For example, an artificial reality system includes a head-mounted display (HMD) configured to output artificial reality content, the HMD including a set of second image capture devices configured to capture image data indicative of a focal point of a gaze of the user and a varifocal display having a focal length that is modifiable based on the focal point of the user. Additionally, the system includes a depth engine configured to generate, based on the real-world image data and depth data associated with the real-world image data, a three-dimensional (3D) scene of the physical environment of the user and generate artificial reality content as an overlay to the 3D scene of the physical environment for display on the varifocal display of the HMD based on the focal point of the user.