Most virtual-reality headsets have their own onboard hardware and screens. An as-yet-unnamed headset from Santa Cruz, Calif., startup Seebright does it a little differently — it uses your smartphones screen and onboard gyroscope and accelerometer to create virtual-reality and augmented-reality experiences. This headset, a prototype for which was revealed at the Game Developers Conference (GDC) in San Francisco, is basically just a head-mounted container for your smartphone, and comes with an eyepiece that reflects the screens images onto your eyes.