'palpebral' originates from Latin, specifically the word 'palpebra', where 'palpebra' meant 'eyelid'.

'palpebra' gave rise in Late/Medieval Latin to the adjective 'palpebralis' (or variants), and this form entered English (via New/Scientific Latin) as 'palpebral'.

Initially it meant 'of or relating to an eyelid', and that anatomical sense has been preserved into modern usage.