  Recent analyses of solar spectroscopic data (see Asplund, Grevesse & Sauval
2004 and references therein) suggest a significative variation of the heavy
elements abundance. The change of heavy mixture might affect the determination
of the clusters age for two different reasons: the change of theoretical
isochrones at fixed metallicity and the variation of the inferred cluster
metallicity from the observed [Fe/H]. The first point is analyzed discussing
the effects of updating the metal distribution on theoretical evolutionary
tracks and isochrones for metallicities suitable for the galactic globular and
open clusters and for the bulk population of the Large Magellanic Clouds. The
maximum variation of the estimated age ($\approx$0.5 Gyr), although not
negligible, is still within the present uncertainty. The second point is
addressed by comparing present theoretical predictions with the very precise
observational data of the Hyades cluster from the Hypparcos satellite.
