The opposite of a concave lens is a convex lens. Contrary to concave lenses, light rays converge in convex lenses. In contrast to the concave lens, the convex lens is bigger in the middle and thinner at the edges, therefore it converges the incident rays into its central axis.
Instead of being bent inward, the convex lens' edges are curved outward. The image seems smaller and inverted when the light is extremely focused beyond the focal length of the lens.
A convex lens's opposite side's center of curvature, , creates the image of an object placed in the center of curvature, , of the lens. As seen in the given illustration, the picture that forms is inverted and the same size as the object.