The captain of the wrecked Costa Concordia cruise liner was not wearing his glasses on the evening of the accident and asked his first officer to check the radar for him, the officer's lawyer said on Saturday.
The cruise liner capsized off the Tuscan island of Giglio after hitting a rock on January 13, killing at least 25 people. Seven people are still unaccounted for.
Prosecutors have accused Captain Francesco Schettino of causing the disaster by bringing the Costa Concordia, carrying more than 4,200 passengers and crew, too close to the shore.
The first officer, Ciro Ambrosio, and seven other officers and executives of the ship's owner, Costa Cruises, are also under investigation.
That evening Schettino had left his reading glasses in the cabin and repeatedly asked Ambrosio to look at the radar to check the route, Ambrosio's lawyer Salvatore Catalano told Reuters outside a pre-trial hearing on the accident on Saturday.
Ambrosio had made the allegation about Schettino, 51, to investigating magistrates at previous hearings, Catalano added.
Schettino has said that the rock hit by the cruise liner was not on his navigational charts and acknowledged that he brought the ship too close to the shore, but he says he was not the only one to blame for the tragedy.
Catalano said Ambrosio ordered the evacuation of the listing vessel before the captain had made up his mind to do it. He ordered the lifeboats to be put to sea from deck number four.
None of those under investigation attended the closed-door hearing in the Tuscan city of Grosseto, which was held in a theatre to accommodate hundreds of victims' relatives, survivors and lawyers for all sides.
Schettino's lawyer, Bruno Leporatti, did not address the latest accusations levelled by the first officer against the captain, who has already been held up to condemnation and ridicule around the world.
But he denounced what he called a media campaign against Schettino and reiterated that his client had constantly informed Costa Cruises' executives of what was happening on the ship.
There has been a media campaign to belittle captain Schettino, but he is not giving in to that ... It's all part of this idea that Schettino is the bad, the dirty and the ugly one, which is absolutely false, Leporatti told a news conference.
Leporatti was asked about an unsourced report in Britain's Daily Mail, which said Schettino had already damaged another cruise ship at a German port in June 2010.
The Daily Mail wrote that Schettino had manoeuvred at a speed of 7.7 to 7.9 knots during entry into the port of Warnemunde, causing damage to the Aida Blu cruise ship.
Leporatti said: That supposed incident was determined by the fact that the (Aida Blu) ship was not moored properly. Schettino was not disciplined by Costa Cruises nor was he notified of any infraction by the port authorities.
In the Costa Concordia case, Schettino is accused of a string of charges including multiple manslaughter and abandoning the liner before the evacuation of passengers and crew. He is under arrest at his home in Meta di Sorrento, near Naples.
His neighbours continued to defend him.
It's normal for accidents to happen at sea, Franco D'Elia, a former sailor, told Reuters. Accidents happen on solid ground, at sea, and in the sky.
(Additional reporting by Laura Viggiano; Editing by Robin Pomeroy and Andrew Heavens)