Although to a contemporary person these appear to be sunglasses, they are not, as they would not be commonly worn until the 20th century.  James Ayscough, an optician in London, England in the 1750s, believed that clear lenses were bad for the eyes, and recommended the use of green or blue ones- an old idea. In 1666, the diarist Samuel Pepys (1633-1703) purchased a pair of spectacles with green lenses, hoping that the tint might relieve his sore eyes caused, he believed, by working in candlelight.