These are two distinct facets. Truly a lens could be either or both plano convex and cylindrical at precisely the exact same time, or not one of those two. Cylindrical lens usually include Plano Convex Cylindrical Lens and Plano Concave Cylindrical Lens.
If we split a double convex lens in just two symmetric components by a plane perpendicular to optical axis we capture 2 plano convex lenses where beams parallel to axis converge at one point. This act just like the first lens but with double the focal length of the first dual convex (curved ) lens. This can be Plano convex (curved ) lens.
Next consider the area enclosed between two arcs at a plane such as the form of a watch. If the lens was created in form of the area extended normally into the plane, we receive a dual convex cylindrical lens, in which the beams converge over a line rather than a point. So while in 1 plane it behaves like routine lens, at the vertical plane it's like plain glass free of curvature. Like preceding case it might be created plano convex cylindrical lens from deviding.
In ordinary camera cylindrical lenses aren't utilized, however in 35mm pictures, added cylindrical lenses have been used to compress image in 1 way, so that with a lens that was similar in the period of projection will give a wide screen image.
In prescription lenses too occasionally there's need to utilize cylindrical lenses clubbed to conquer relevant deformity.
We will talk about Convex Cylindrical Lens, Plano Concave Cylindrical Lens and other optical lens in next news.