A method for determining an eye position of a user comprrising: illuminating a portion of an eye of a user with a coherent light source mounted inside a VR headset; capturing an image of light from the light source reflected by a portion of the eye with a camera mounted inside the VR headset; determining a position and an orientation of the eye of the user based on the captured image of light from the light source reflected by the portion of the eye and stored calibration data including a subpixel distance indicating a distance on a surface of the portion of the eye of the user corresponding to a subpixel of an image sensor included in the camera and one or more previously captured images of light from the light source reflected by the portion of the eye of the user; and providing the eye position to one or more components of a system environment configured to provide content to the VR headset based on the determined eye position wherein determining an eye position of the eye of the user based on the captured image of light from the light source reflected by the portion of the eye and stored calibration data comprises: extracting surface features from the captured image of light from the light source reflected by the portion of the eye, the surface features being diffraction patterns of coherent light associated with an eye surface of the portion of the eye; comparing the extracted surface features to corresponding said surface features extracted from at least a set of the one or more previously captured images of light from the light source reflected by the portion of the eye of the user; selecting a previously captured image of light from the light source reflected by the portion of the eye of the user associated with a reference eye position based on the comparison; determining a subpixel shift between the surface feature of the captured image of light from the light source reflected by the portion of the eye of the user and the surface feature of the selected previously captured image of light from the light source reflected by the portion of the eye; and determining a position of the eye of the user as a product of the subpixel shift and the subpixel distance. illuminating a portion of an eye of a user with a coherent light source mounted inside a VR headset; capturing an image of light from the light source reflected by a portion of the eye with a camera mounted inside the VR headset; determining a position and an orientation of the eye of the user based on the captured image of light from the light source reflected by the portion of the eye and stored calibration data including a subpixel distance indicating a distance on a surface of the portion of the eye of the user corresponding to a subpixel of an image sensor included in the camera and one or more previously captured images of light from the light source reflected by the portion of the eye of the user; and providing the eye position to one or more components of a system environment configured to provide content to the VR headset based on the determined eye position wherein determining an eye position of the eye of the user based on the captured image of light from the light source reflected by the portion of the eye and stored calibration data comprises: extracting surface features from the captured image of light from the light source reflected by the portion of the eye, the surface features being diffraction patterns of coherent light associated with an eye surface of the portion of the eye; comparing the extracted surface features to corresponding said surface features extracted from at least a set of the one or more previously captured images of light from the light source reflected by the portion of the eye of the user; selecting a previously captured image of light from the light source reflected by the portion of the eye of the user associated with a reference eye position based on the comparison; determining a subpixel shift between the surface feature of the captured image of light from the light source reflected by the portion of the eye of the user and the surface feature of the selected previously captured image of light from the light source reflected by the portion of the eye; and determining a position of the eye of the user as a product of the subpixel shift and the subpixel distance. extracting surface features from the captured image of light from the light source reflected by the portion of the eye, the surface features being diffraction patterns of coherent light associated with an eye surface of the portion of the eye; comparing the extracted surface features to corresponding said surface features extracted from at least a set of the one or more previously captured images of light from the light source reflected by the portion of the eye of the user; selecting a previously captured image of light from the light source reflected by the portion of the eye of the user associated with a reference eye position based on the comparison; determining a subpixel shift between the surface feature of the captured image of light from the light source reflected by the portion of the eye of the user and the surface feature of the selected previously captured image of light from the light source reflected by the portion of the eye; and determining a position of the eye of the user as a product of the subpixel shift and the subpixel distance.