An eyes-only file is top secret.
eyes-only definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
Informal confidential: said of a business or government report, memorandum, etc. not to be made public
eyes-only definition by American Heritage Dictionary
Of or relating to privileged information: “Never before . . . had he been ordered to write a secret eyes-only memo” (Jeff Kamen).
Origin: From the phrase for your eyes only.