The principle of operation is to stimulate the retina with laser speckle patterns in the green and red spectra, respectively, of the spectral sensitivity of the photoreceptors of the retina. Stimulation is also used when mixing speckle structures of radiation in the green and red spectra. The effectiveness of treatment is evaluated by the parameter of the critical frequency of flicker fusion. The speckle structures increase visual acuity, as well as relieve spasm as a result of vasodilation of blood vessels, which leads to improved blood microcirculation. It is used to treat amblyopia of various origins, to relieve visual fatigue when working on a computer or when wearing contact lenses.