Variant: or 20/20
Pronunciation: - ' twen-t ē , - ' tw ə n-
Function: adjective
Etymology: from the testing of vision by reading letters at a distance of 20 feet
Date: 1875
1 of the human eye : meeting a standard of normal visual acuity < twenty-twenty vision>
2 : marked by facilely accurate discernment, judgment, or assessment <hindsight is twenty-twenty >