'astigmia' originates from New Latin and Greek, specifically from the Greek term 'astigmatismos' (from the elements 'a-' + 'stigma'), where 'a-' meant 'without' and 'stigma' meant 'a point' or 'mark'.

'astigmia' changed from 19th-century medical Latin/New Latin forms such as 'astigmatismus' and 'astigmatismos' and was used in English as a variant form alongside 'astigmatism'.

Initially it referred to the optical notion of the 'absence of a single focal point' in optics; over time it came to denote the clinical eye condition now commonly called 'astigmatism' — a refractive defect causing blurred or distorted vision.