PENNSYLVANIA • The sight of 78-year-old Bill Cosby walking with a cane into a Pennsylvania courthouse as he held the hands of his lawyers on Wednesday was in stark contrast to the spry, wisecracking 1980s TV father most Americans remember.

The comedian, who faces a charge of sexually assaulting a woman in 2004 and public accusations from more than 50 women of sexual assaults dating back decades, appeared frail and seemed to have trouble with his vision. His lawyers called Wednesday's charge "unjustified" and promised a vigorous defence.

He had also stumbled as he walked into the courthouse in Elkins Park, Pennsylvania. Reporters in the courtroom, where Cosby was arraigned on Wednesday, said he appeared to have trouble seeing the paperwork. His lawyers helped him hold a pen.

In a defamation lawsuit against one of his accusers earlier this month, Cosby said he has been legally and functionally blind for a year because of a degenerative eye condition that he has suffered for years, reports said.

He was on Wednesday charged with sexually assaulting in 2004 his former Temple University associate Andrea Constand in his home in Cheltenham, Pennsylvania. He pleaded not guilty. It was the first time he has faced a criminal charge following years of complaints against him from women.

He was charged with aggravated indecent assault, a second-degree felony carrying a maximum penalty of five to 10 years in prison and a US$25,000 (S$35,300) fine. He posted bail of US$1 million and a hearing was set for Jan 14.

According to an affidavit accompanying the charge, Ms Constand was a guest at Cosby's home in 2004 when he gave her wine and urged her to take three blue pills, prosecutors said in a statement. "Shortly thereafter, the victim became incapacitated and Cosby led her to a couch. The victim lay down... and Cosby positioned himself behind her."

The prosecutors also accused him of fondling her and penetrating her with his fingers.

REUTERS