This is the ordinary magnifying glass.

In this magnifier the center of each plano-convex lens is located at the focal point of the other.

This lens is created from a sphere. The groove cut into the cylindrical side of the lens provides a stop, thus improving the quality of the image it creates.

This type of structure produces the best type of magnifiers. They have a relatively large working distance.

This is another type of structure which produces the best type of magnifiers. They have a relatively large working distance and, as the name indicates, can be designed so asto eliminate chromatic aberration.