Easton's Bible Dictionary
Covering of the eyes
Occurs only in Genesis 20:16. In the Revised Version the rendering is "it (i.e., Abimelech's present of 1, n000 pieces of silver to Abraham) is for thee a covering of the eyes." This has been regarded as an implied advice to Sarah to conform to the custom of married women, and wear a complete veil, covering the eyes as well as the rest of the face.
Noah Webster's New International Dictionary of the English Language
1. (p. pr. & vb. n.) of Cover.
2. (n.) Anything which covers or conceals, as a roof, a screen, a wrapper, clothing, etc.