What you should know about low vision vs. legal blindness
"Legal blindness" is a definition used by the United States government to determine eligibility for vocational training, rehabilitation, schooling, disability benefits, low vision devices, and tax exemption programs. It's not a functional low vision definition and doesn't tell us very much at all about what a person can and cannot see.
Part 1 of the U.S. definition of legal blindness states this about visual acuity: