Embodiments of the present disclosure are directed to a phototherapy eye device. In an example, the phototherapy eye device includes a number of radioluminescent light sources and an anchor. Each radioluminescent light source includes an interior chamber coated with phosphor material, such as zinc sulfide, and containing a radioisotope material, such as gaseous tritium. The volume, shape, phosphor material, and radioisotope material are selected for emission of light at a particular wavelength and delivering a particular irradiance on the retina (when implanted in an eyeball). The wavelength is in the range of 400 to 600 nm and the irradiance is substantially 109 to 1011 photons per second per cm2.