Changes in mean-square nuclear charge radii, δ〈 r 2〉, are extracted from reported optical isotope and isomer shifts. Allowance for specific mass shifts is made and different methods for doing this are discussed. The change of the electronic charge density at the nucleus is evaluated by means of empirical data as much as possible. Whenever feasible, δ〈 r 2〉 is determined from isotope shifts measured in various electronic transitions as well as in different spectra of an element. Relative and absolute values of δ〈 r 2〉 are given in the Tables and are compared with δ〈 r 2〉 values obtained from electronic x-ray isotope shifts. There is fair agreement in most cases.