Perhaps this is Solarbabies, an Action/Sci-Fi movie from 1986.
According to this Wikipedia plot summary:
The story is set in a post-apocalyptic future in which most of Earth's
water has been controlled. The future is bleak and is controlled by
the Eco Protectorate (a para-military organization that governs the
planet's new order). There are also children, mostly teenagers, living
in orphanages created by the Protectorate, designed to indoctrinate
new recruits into their service. [...] The orphans play a rough sport which is a hybrid
of lacrosse and roller-hockey. Playing is the only thing that unites
them other than the futile attempts of the Protectorate to control
While hiding in a cave, Daniel finds a mysterious orb with
special powers. The orb is an alien intelligence called Bohdai, who
miraculously restores Daniel's hearing and has other powers, such as
creating rain indoors.