An anopsia (from Ancient Greek ἀν- (an-) 'without', and ὄψις (opsis) 'sight') is a defect in the visual field. If the defect is only partial, then the portion of the field with the defect can be used to isolate the underlying cause.

Types of partial anopsia:

• Hemianopsia
  • Homonymous hemianopsia
  • Heteronymous hemianopsia
    • Binasal hemianopsia
    • Bitemporal hemianopsia
  • Superior hemianopia
  • Inferior hemianopia
• Quadrantanopia