means Tinted glasses worn over the eyes to shield them from bright sunlight and glare.

from A transparent compound: 'sun' from Old English 'sunne' joined to 'glasses,' the plural that came to mean spectacles after glass lenses were ground for the eyes. The word is fairly modern — it arrives once mass-produced tinted eyewear made shading your eyes a fashion as much as a function, in the early 20th century. Tinted lenses themselves are far older: smoke-colored quartz spectacles were used in China centuries ago, the popular story goes, to hide a judge's expression in court — a fitting ancestor for an object built to keep others from reading your eyes.