Each light ray entering a diverging (concave) lens refracts outwards as it enters the lens and outwards again as it leaves. These refractions cause parallel light rays to spread out, travelling directly away from an imaginary focal point.
Each light ray entering a diverging (concave) lens refracts outwards as it enters the lens and outwards again as it leaves. These refractions cause parallel light rays to spread out, travelling directly away from an imaginary focal point.