Canadian detainee Omar Khadr attended a pre-trial hearing in Guantanamo Bay Thursday afternoon, after he refused to appear in court all morning.

Capt. Laura Bruzzese, a military spokeswoman at Guantanamo, said the 23-year-old Khadr objected to new security rules at the U.S. military facility where he has been held for nearly eight years.

CTV's Lisa LaFlamme said that Bruzzese told the judge in the case that Khadr refused to put on what Guantanamo guards call "eyes and ears" -- a set of blacked-out goggles and earmuffs for the short van ride from his cell to the courtroom.

"What's the reason for me to wear it?" she testified that Khadr said. "It's humiliating ... you're trying to humiliate me."

However Barry Coburn, one of Khadr's lawyers, said he was "in extreme pain'' because of a flare-up of conjunctivitis in his eyes.

The condition is related to shrapnel still lodged behind his eyes from a firefight in Afghanistan in July 2002, in which he is accused of throwing a grenade that killed a U.S. soldier.

He was 15 years old at the time, and has been in custody ever since.

During Thursday's hearing, Khadr sat slumped in his chair, dabbing at his eyes and covering his face as the afternoon session began.

Khadr has boycotted proceedings in the past and military judge Col. Patrick Parrish ruled that the hearing would continue, whether or not Khadr was present.

The judge urged Khadr's lawyers to talk to him and warned he could be brought to court by force in order to be advised of his right to attend the hearings.

His case is serving as a test run for the U.S. military justice system, which is supposed to process the remaining Guantanamo detainees so that Washington can shut down the controversial prison.

"Politically this is something that everyone wants to end," LaFlamme said. "The trial is supposed to start in July, but given what's happened just in the last three days it's just impossible … to even predict what the next phase in this is going to be."

On Wednesday, his lawyers turned down a purported deal that would have seen their client serve five years in a U.S. prison as a trade-off for pleading guilty to war crimes offences.

The pre-trial hearing is to determine whether or not to admit key evidence -- a video that appears to show a young Khadr learning how to build a roadside bomb.

Under the U.S. Military Commissions Act of 2009, evidence that is obtained through cruel, inhumane or degrading treatment of a prisoner is not admissible and Khadr's lawyers say that under these rules, the video should not be allowed as evidence.

"If the judge does decide to suppress that evidence, the prosecution case falls apart," LaFlamme said.

At least 30 witnesses are scheduled to testify at the hearing.