Blue light has a shorter wavelength and thus focuses slightly in front of the retina. Therefore, when it hits the retina it's slightly out of focus, i.e. fuzzy. Think of what it's like when you look at a UV lamp, only not so extreme. Filtering that light out gives the impression of sharpening your vision. In certain conditions it can make quite a difference. Fact attack.
Blue light has a shorter wavelength and thus focuses slightly in front of the retina. Therefore, when it hits the retina it's slightly out of focus, i.e. fuzzy. Think of what it's like when you look at a UV lamp, only not so extreme. Filtering that light out gives the impression of sharpening your vision. In certain conditions it can make quite a difference. Fact attack.