Spherical lens : reflect surface is the part of spherical.It is an optical device with chransmits and refracts ligh,converging or diverging the beam. 

Spherical lenses are two main types.They are convex lens and concave lens. 

The convex lens is thicker in the middle and thinner in the edge.The light parallel to the spindle is refracted by the point(converging) of the convex lens on the sprindle. 

The concave lens is thinner in the middle and thicker at the edge.After the refraction diverges.The light of parallel to the spindle appears from the point axis on the ipsilateral side of the lens. 

Plano Convex spherical lenses    Plano concave spherical lenses    Double convex spherical lenses

Double concave spherical lenses     Meniscus spherical lenses     Achromatic spherical lenses