US Patent 10180769 Symbol display

A method of in-eye icon projection using an electronic device includes emitting light with a light source in response to detecting an image condition. The light is then projected onto a diffraction grating, and the diffraction grating, when illuminated with the light, produces image light of a fixed icon. An image of the fixed icon is formed in an eye of a user, and the image of the fixed icon occupies only part of the user's field of view. The image light has a limited divergence such that the image of the fixed icon is only viewable in a single user's field of view.