Leonard McCoy gave Admiral James T. Kirk a pair of reading glasses on his birthday, because Kirk has an allergy to Retinax.
When the crew travelled back in time to 1986, they needed money. Kirk went to a pawn shop with Spock and exchanged the glasses for $100. He would have received more if both lenses were intact.
The glasses were part of the Museum of the Future and Star Trek: The Experience in the Hilton in Las Vegas, Nevada