The Spanish word 'optometría' (optometry) comes from combining two Ancient Greek elements: 'ὀπτός' (optos) meaning 'visible' and '-μετρία' (-metria) meaning 'measurement'. These elements were joined to create a term that literally means 'measurement of vision', reflecting the medical practice of examining and measuring eye function.

Some related Spanish words include 'óptico' (optical), 'óptica' (optics/eyewear shop), and 'ojo' (eye). While 'óptico' and 'óptica' share the same Greek root 'optos' for vision, 'ojo' comes from a different etymology (Latin 'oculus') but belongs to the same semantic field of vision and sight.

English speakers can easily relate this word to several familiar terms like 'optometry', 'optical', and 'optics', which all share the same Greek root 'optos'. The '-metry' portion appears in many English words involving measurement, such as 'geometry' (measurement of earth), 'symmetry' (measurement of sameness), and 'thermometry' (measurement of temperature).