The aim of this monocentric randomized controlled intervention study is to improve visual function in persons with multiple sclerosis following optic neuritis (neuritis nervi optici) by means of a light stimulation. In the treatment arm, two 80-second light stimulations are to be administered daily for 12 days in 25 persons with multiple sclerosis following recent optic neuritis (1-3 months). For the standardized application of light stimulation in the sense of standardized training, the light stimulation is to be carried out by watching a generated flicker video on a mobile phone. In a sham-intervened control group (sample size 25), the spontaneous course after optic neuritis will be recorded in parallel. Intensive neuronal stimulation of the visual pathway will be used to stimulate regenerative processes, which will be recorded by means of changes in high-contrast visual acuity (primary endpoint). Secondary endpoints are changes in a colored-contrast test, in 2.5% low contrast visual acuity, the peak conduction latency of visual evoked potentials, and retinal layer thicknesses and vessel densities measured in optical coherence tomography and optical coherence tomorgraphic angiography. These physiological parameters should help to understand the underlying processes of a potentially altered visual performance.