Anopsia
（重定向自Anopia）
An anopsia or anopia 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:
The term anopsia comes from the Ancient Greek ἀν- (an-), "un-" and ὄψις (opsis) "sight".