When a set of parallel rays enter a biconcave lens or a plano concave lens,. it diverges the light rays on the other side of the lens. Hence, a. biconcave or a plano concave lens is called a diverging lens. Except. these divergent rays give an impression that they emerge from a point on. the axis at the same side of entry of the rays. It is simply a virtual point. as we will as not real. This point is called the focus as we will as it is distance from the. lens is called focal length of the concave lens. Do you know why today’s lenses are used instead of spectacle? Lens is simply a handy optical device which is now widely used in daily life as we will as in place of spectacle. Lens has capacity for reflection of light as we will as form a clear image. This is similar to mirror as we will as used in various purposes as we will as in optical instrument like telescope, microscope etc. it is formed with transparent material. It easily refracts light from it is each boundary. When a light strike on a lens then it gets reflected as we will as at the same time, a beam of light has also existed from the lens. Because of this, a beam of light changes it is direction. This is all because of the fact that of it is special geometry. Now we discuss what types of lenses, how they work to form an image, as we will as the refraction process of converging as we will as diverging lenses.