What affliction involves a limitation of visual field to no more than 20 degrees?

Legal blindness is defined as having a visual acuity of 20/200 or worse in the better eye with corrective lenses, or a visual field limitation of less than 20 degrees. This condition significantly impacts daily functioning and qualifies individuals for certain services and protections under disability laws. The 20-degree visual field restriction indicates a profound loss of peripheral vision, making it difficult for an individual to see objects outside this limited scope. This is distinct from other conditions listed, which do not have the same strict visual field criteria or do not pertain to the same level of visual impairment. Partially sighted refers to individuals who have some vision but do not meet the criteria for legal blindness. Hyperopia is a refractive error causing difficulty seeing close objects, while diplopia refers to double vision. Each of these terms addresses different aspects of vision impairment, but legal blindness specifically encompasses the limitation of visual field to 20 degrees or less.