Burleigh County Sheriff's Maj. Les Witkowski says the 42-year-old inmate at the county detention center became frustrated Aug. 1 when he was not able to talk to the chaplain, so he swallowed both lenses and a piece of the metal frame.
He had been booked on an aggravated assault charge just five hours earlier.
Witkowski says the inmate was taken to a hospital emergency room but was returned to jail after doctors determined he was OK.
The glasses were worth $250. Authorities are considering a criminal mischief charge against him.
Assistant State's Attorney Lloyd Suhr says he'll be looking into the incident.