🔭 A lens telescope 👓 Vision tester 💡 A light bender

$refractor$

refractor

1 7.3

A machine that eye specialists use to test vision and find the right glasses

noun
/rɪˈfræktər/

Specialized

: refractómetro

Examples

Well, now, I was only testing the refractor.

The Wolf Man (1941)
The eye doctor used a refractor to check my vision and update my glasses prescription.
With the refractor in hand, the optometrist assessed my eyesight during the eye exam.
During my appointment, the technician explained how the refractor helps determine the best lens for my glasses.

Surface Forms

refractor singular

refractors plural

Morphology

refractor = refract (transparent) = refract + or

Specialized instrument sense (used by eye-care professionals) is derived by standard noun formation from 'refract' + '-or', so the morphological relation is transparent even if the use is technical.

Etymology

Refractor comes from the Latin parts re- 'back' and frangere 'to break', like the root in fracture. That is why a clinic refractor is a device that bends light to test your eyesight and find the right lens.