Macro lenses
Macro lenses are fixed focal length lenses whose working distance is comparable to their focal length. The recommended working distance from the object is usually fixed, hence macro optics are usually described by their magnification.
Since macro lenses are specifically designed to image small and fixed FoVs, they tend to have extremely low geometrical distortion. For example, the distortion of Opto Engineering® MC series lenses range from <0.05% to <0.01%.