Legally blind is usually defined as having a visual acuity of 20/200 that cannot be improved with corrective lenses or having a visual field of less than 20 degrees.

• A. Visual acuity 20/20 with full field.
• B. Visual acuity 20/200 that cannot be improved with corrective lenses or a visual field less than 20 degrees.
• C. Visual field 90 degrees.
• D. Vision loss corrected with lenses.

Answer: (B)

Legal blind­ness is defined by two criteria: either very reduced central vision that cannot be corrected to normal, or a severely restricted visual field. The key threshold is 20/200 or worse in the better eye with the best possible correction, or a visual field of 20 degrees or less. The statement that describes acuity at 20/200 that cannot be improved with corrective lenses, or a field under 20 degrees, matches these official criteria exactly. This is why it’s the best answer: it reflects the standard definition used to determine legal blindness and emphasizes that correction cannot bring acuity to a normal level and that a very limited visual field also qualifies. The other options don’t meet these criteria: normal acuity with a full field is not blind; a 90-degree field is not below the 20-degree threshold; and vision loss that can be corrected with lenses does not satisfy the “cannot be improved” condition.