A visual ability improvement supporting device includes a noise outputting device and a noise generating device. The noise generating device generates noise with intensity which is optimum to a threshold intensity of visibility. The optimum intensity is optimum to induce stochastic resonance (SR). The noise outputting device includes a room lighting device, which illuminates a surrounding area when a lighting switch is turned on, and outputs the visual noise according to the generated noise even when the lighting switch is turned off not to illuminate the surrounding area.