The first officer of the Costa Concordia says the captain of the Italian cruise ship left his reading glasses in his cabin on the evening the vessel hit a rock off the Tuscan coast and asked him to set up the ship's radar.

The officer, Ciro Ambrosio, made the comment in testimony given to the prosecutor as a pre-trial hearing into the Jan. 13 disaster was getting underway Saturday in the Tuscan town of Grosseto.

The captain, Francesco Schettino, faces charges of causing a shipwreck, manslaughter and abandoning ship while it sank, but denies wrongdoing. His lawyer says Schettino will not be attending the hearing and remains under house arrest in Meta di Sorrento, his hometown near Naples.

Ambrosio and seven others — four officers from the cruise liner and three executives of the ship's owner, Costa Cruises — are also under investigation, but no one has been formally charged.

Costa Concordia first officer Ciro Ambrosio leaves the prosecutor's office on Jan. 27 after being heard in regard to the cruise ship's grounding. (Giacomo Aprili/Associated Press)

Prosecutors allege the captain caused the accident by sailing the Costa Concordia too close to land to perform a naval manoeuvre called a "salute" for islanders on Giglio.

Ambrosio told investigating magistrates that Schettino did not have his glasses on when he steered the ship closer to the island.

"When he took command of the bridge he didn't have his glasses with him because he'd left them in his cabin. He asked me to set up the radar because he wasn't able to see very well," Ambrosio said.

The first officer's lawyer, Salvatore Catalano, quoted his client as saying the captain "repeatedly" asked Ambrosio to look at the radar to check the route.

Seventeen people were killed and 15 are missing and presumed dead in the accident, when the grounding tore a hole in the ship's the hull. The 289-metre-long vessel remains resting on its side.

The luxury liner was carrying 4,229 people from dozens of countries when it crashed and began taking on water, including 12 Canadians who made it out safely.

Hundreds of people, mostly consultants and the lawyers for former passengers and crew members, are in Grosseto for the hearing.

Experts in attendance were to be handed all of the evidence collected by investigators, including more than 5,000 pages of witness testimony. The two naval experts and two academics on the court-appointed panel of experts were given access to the ship's voice and data recorder.

The pre-trial hearing is being held inside a theatre that can hold more than 600 people, but the proceedings will remain closed to journalists and the public.

The panel of experts is expected to spend months sifting through the evidence to establish exactly what happened in the vessel's disastrous final moments.

Francesco Verusio, the prosecutor leading the Italian investigation, says it could take experts three months just to analyze the ship's voice and data recorder.