As the first day of Bill Cosby's sexual assault trial kicked off on Monday, June 5, fans struggled to understand how the man once dubbed "America's Favorite Dad" had fallen so far.

Those following the comedian's court case were surprised to see how much his health has deteriorated since allegations of rape first resurfaced in October 2014.

MORE: Bill Cosby's Mugshot Released Following His Arrest For Sexual Assault

The 79-year-old told Black Press USA in April that he is now completely blind. A source revealed to Page Six last year that "his alleged victims may take some solace in the fact that he's in his own personal hell. He has been suffering from a degenerative eye disease…"

Although Bill's former TV daughter, Keshia Knight Pulliam, walked into the Norristown, PA, courtroom with him, the source said that most of "his Hollywood friends have turned their backs on him… His only friends are the small army of lawyers on his payroll."

bill cosby keshia knight pulliam getty images

Bill and his Cosby Show daughter Keshia Knight Pulliam arriving at the courtroom on June 5.

The Cosby Show alum is currently on trial for an alleged 2004 attack against Andrea Constand. The former Temple University employee claims she was first drugged by the actor.

In a lengthy letter published earlier this year, Bill's youngest daughter, Evin, defended her father, writing, “The public persecution of my dad, my kids’ grandfather, and the cruelty of the media and those who speak out branding my father a ‘rapist’ without ever knowing the truth… makes all of this so much worse for my family and my children."

MORE: See What the Cast of 'The Cosby Show' Looks Like Today

She added, "When people are so quick to cast hate and make accusations of horrific violence against my dad, they are callous in their carelessness about the harm they are causing to others."

A TV special about his downfall, titled Bill Cosby: An American Scandal, airs Monday, June 5, at 9 p.m. EST on Investigation Discovery.