Atomic structure is a very valuable probe of nuclear properties. For example, hyperfine splitting of atomic levels was early on used to deduce nuclear spin and magnetic dipole moments. More recently, and by abandoning the infinite-mass point-like nucleus approximation, differences in rms radii in isotopes have been confirmed and derived by comparing results from atomic structure calculations with observations. Meaningful extraction of nuclear properties has, however, partly been hampered by a lack of accurate and systematic data for the atomic mass shift. During the last few years there has been an advancement in the theoretical description of the mass shift as well as in computational techniques and with more precise experimental information this allows for accurate determination of previously known nuclear properties as well as new insights into details of the nuclear charge distribution. Together with an overview on "atomic structure close to the nucleus", a new formulation of the field shift is presented which have the potential to probe the shape of the nuclear charge distribution.