In this paper we have followed the evolution of theoretical
predictions concerning Pop. II stellar models vis-a-vis the recent
progress in the input physics. Stellar models including all
the more recent evaluations of theoretical ingredients have been
presented and discussed, with particular regard to the problem of
globular cluster ages. We found that these models tend to decrease
previous estimates about the cluster age. The account for element
sedimentation goes in the same direction. As a whole one finds that
"canonical age estimates", as given in CCP, have to be decreased by
about 4 Gyr, promising a much better agreement with cosmological
constraints.
We finally drew attention to the large uncertainty of the
theoretical procedure adopted to constrain the cluster original abundance
of He, concluding that accurate results on that subject must wait for
a better determination of the nuclear cross section 12C + 
.
Detailed tabulations on both evolutionary tracks and/or cluster
isochrones are available upon request by E-mail.
Acknowledgements
It is a pleasure to thank F. D'Antona for her comments on a preliminary draft of the paper.