Which measure of visual acuity is categorized as legal blindness?

Legal blindness is defined in the United States as having a visual acuity of 20/200 or worse in the better eye with the best possible correction. When someone has vision that measures 20/200, it means that what a person with normal visual acuity can see at 200 feet, this individual can only see at 20 feet. This significant reduction in vision demonstrates a level of impairment that qualifies for legal blindness under various regulations and aid programs.

Measures such as 20/100 and 20/50 indicate better vision than 20/200, therefore those do not meet the criteria for legal blindness. The measure of 20/400 indicates even poorer vision than 20/200, but it is generally classified within the broader spectrum of visual impairment rather than legal blindness specifically. Thus, the definition and standard for legal blindness clearly align with the 20/200 measurement, establishing it as the correct answer.