Lawyers for Bill Cosby are arguing that the comedian is “legally blind” and therefore can’t identify his sexual assault accusers, reported NBC News. Cosby’s legal team made the written claim in a court document filed in Pennsylvania on Thursday. Cosby’s team was recently accused of attempting to hide Cosby’s “true nature” to get the case dismissed.

"No 79-year-old blind man could possibly defend himself against a claim that he sexually assaulted someone he supposedly met once, half a century ago," wrote Cosby’s lawyers Brian McMonagle and Angela Agrusa. In the brief, obtained by People, the lawyers wrote: “The answer is simple: He cannot, and the Commonwealth knows he cannot… Without his eyesight, Mr. Cosby cannot even determine whether has has ever even seen some of his accusers, let alone develop defenses and gather exculpatory evidence. Moreover, Mr. Cosby’s memory has substantially declined in the last decade.”

Besides writing that Cosby is registered as legally blind in Massachusetts, attorneys said they would provide documentation from a doctor affirming that he is legally blind. However, prosecutors have said Cosby could still assist his legal team despite his blindness.

Cosby is standing trial for the 2004 alleged sexual assault of Andrea Constand, who accused the star of drugging her and sexually assaulting her in his home. If convicted, Cosby could face up to 10 years in prison. Prosecutors are reportedly looking to call at least 13 other women who have accused Cosby of sexual assault as witnesses, reported NBC News.

A pretrial hearing for the case starts Tuesday.