acies
nounEtymology Borrowed from Latin aciēs (“edge, sharpness”).
1
Obsolete The full attention of one's sight, hearing or other senses, as directed towards a particular object.
- 1658: And therefore providence hath arched and paved the great house of the world, with colours of mediocrity, that is, blew and green, above and below the sight, moderately terminating the acies of the eye. — Sir Thomas Browne, The Garden of Cyrus (Folio Society 2007, p. 204)