In a footnote within the motion filed Thursday, Cosby's attorneys say he is "legally blind" -- which means he has a vision of 20/200 or less in the better eye, according to the Massachusetts Commission for the Blind -- and has registered with the state Commission. A copy of a doctor's report will be provided at the next hearing in the case, set for Tuesday.
Cosby faces three charges of felony indecent assault stemming from a 2004 incident involving Andrea Constand, an employee at his alma mater, Temple University.
Defense attorneys say prosecutors have "chosen to turn this case into a platform for Mr. Cosby's other accusers to air their even staler, long-ago time-barred claims that were never reported to authorities."
Bill Cosby, who his lawyers now say is legally blind, has been escorted into his recent court hearings on the arms of his representatives.
"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 -- and the Commonwealth knows it," they say.
The defense argues "without his eyesight, Mr. Cosby cannot even determine whether he has ever even seen some of his accusers, let alone develop defenses and gather exculpatory evidence."
The motion is part of an effort to get the charges dismissed.
A tentative trial date has been set for June 5.
Prosecutors haven't responded to this latest motion but in previous court filings regarding requests for a dismissal, attorneys for the state have said that the defense's arguments are part of a pattern Cosby employs to use his "fame and fortune" to cover up his crimes and "hide his true nature."