Only days before President Obama revealed that his worst fear was a nuclear terror attack on Manhattan, a nearly blind guard was caught sleeping on the job at the Freedom Tower — where he was the building’s first line of defense.

In this cellphone photo obtained exclusively by The Post, Abdul Basher, 65, is wearing shades and lying almost completely horizontal in a chair in the No. 1 terror target’s south lobby, where he was the only guard stationed, sources said.

Even when awake, Basher admittedly can’t open his left eye and has “hazy” vision out of his right due to a nerve condition.

“Sometimes I cannot recognize people, stairs,” Basher said. “That post was so hard to cover for me. It was very, very stressful. I could barely see half of the lobby.”

A Port Authority worker spotted Basher snoozing on duty at around 2:45 a.m. Saturday — six days after a New Jersey teenager slipped past another sleeping guard on the 104th floor of the building on the way to the spire, sources said.

Basher was fired on the spot, suffering the same fate as the guard on duty when the high-schooler got through.

The shop steward for SEIU ­Local 32BJ said Basher — named the union’s “Security Officer of the Year” for 2013 — was “just getting ready to go on disability.”

His nap-time photo emerged a day after Obama shrugged off Russia as a major US security threat, saying that he was more concerned about a nuclear attack on New York City.

Basher said he was stunned that his bosses put him in charge of such a sensitive location — and had been expecting merely to guard a stairwell door that night.

“The security division is so poorly managed . . . Every security guard that works for them is mentally stressed,” he said.

The Bangladeshi immigrant with some missing teeth also claimed he hadn’t been dozing.

“To my knowledge, actually I was not sleeping. I was mistaken to be sleeping. I was exercising my eyes,” he insisted.

The PA, the owner of the site, referred all questions to the Durst Organization, which supplies guards in 1 World Trade Center.

A high-ranking PA insider called the incident “troubling” and said Durst execs would be called on the carpet.

Durst spokesman Jordan Barowitz confirmed that Basher “was terminated on the spot after he was found sleeping on the job.”

Barowitz refused to specify what measures, if any, would be taken to prevent future security screw-ups.

Construction workers at Ground Zero were appalled by the photo. “There’s our hardworking security right there . . . What a joke!” one said.

Additional reporting by Kevin Fasick