QED contributions to the atomic structure at strong central fields

Precise determination of the accurate structure of highly charged, very heavy ions is the basis for a detailed understanding of QED at strong fields. The experimental advances in this field will be reviewed with special emphasis given to H-, He- and Li-like very heavy ions. For the heaviest species, U, the ground-state Lamb shift for H-like ions is measured with an accuracy of about 1%, the two-electron QED terms for He-like system are just being touched, and for the Li-like species already two-loop QED terms have been probed with ultimate accuracy. The different approaches to measure the strong field QED contributions will be elucidated and the results compared to theory. Emphasis will be given to results from the heavy ion storage ring ESR.