'emmetrope' originates from Greek, specifically the word 'emmetros,' where 'en-' meant 'in' and 'metron' meant 'measure,' combined with '-ops' meaning 'eye.'

'emmetros' and '-ops' combined in scientific Latin to form 'emmetropos,' which became the modern English word 'emmetrope.'

Initially, it meant 'having eyes in proper measure,' but over time it evolved into its current meaning of 'a person with normal vision (no refractive error).'