'asthenopic' originates from Neo-Latin/Greek, specifically the word 'asthenopia', where 'asthen-' meant 'weak' and 'ops'/'opia' meant 'eye' or 'vision'.

'asthenopia' comes from Greek elements 'asthenēs' (weak) + 'ōps' (eye, vision); it passed into New Latin as 'asthenopia', and English formed the adjective 'asthenopic' by adding the suffix '-ic'.

Initially it referred specifically to 'weakness of the eyes' or 'eye fatigue'; over time it kept this specialized medical sense and is now used adjectivally to mean 'relating to or showing eye strain'.