The definition of the focal length of a converging lens is the distance to the point where rays initially parallel to the axis meet after passing through the lens. Rays going through the focus (or com...The definition of the focal length of a converging lens is the distance to the point where rays initially parallel to the axis meet after passing through the lens. Rays going through the focus (or coming from the focus if the object is closer to the focus) bend to exit the lens parallel to the axis; and 3.