'anopsia' originates from New Latin, ultimately from Greek 'anōpsia', where 'an-' meant 'without' and 'opsis' meant 'sight' or 'vision'.

'anopsia' entered English via New Latin/medical Latin from the Greek word 'anōpsia' (ἀνώψια), which itself is formed from the prefix 'an-' and 'opsis'.

Initially it meant 'absence of sight' in the Greek formation, and it has retained essentially the same medical meaning in modern English: loss of vision (often localized to part of the visual field).