PbO-containing ternary and multicomponent glasses were fused together and reacted at temperatures between 1000 and 1500 degrees C. Those samples which were stable both against crystallization and convection could be evaluated to give an effective binary diffusion coefficient, D-Pb,D-m. This quantity was used then to set up a simple scheme to interrelate layer thickness, annealing time and annealing temperature for choosing a suitable multilayer glass package for the preparation of gradient index lens blanks. Both three-layer and six-layer packages were tested, and it could be shown that with a suitable six-layer package the gradient in PbO may be tailored as desired, e.g. in a linear or a parabolic way.