The Collaborative International Dictionary
Optometer \Op*tom"e*ter\, n. [Optic + -meter.] (Physiol.) An instrument for measuring the distance of distinct vision, mainly for the selection of eveglasses.
Wiktionary
n. An instrument for measuring the focus of the lens of the eye.
Wikipedia
Optometer may refer to:
- Autorefractor, a modern electronic instrument for automatically refracting vision for eyeglasses.
- Optometer (ophthalmic instrument), the earliest name for a phoropter, for refracting vision for eyeglasses.
A device, used for measuring spherical and/or cylindrical prescription for eyeglasses, from the middle of the 18th century until around 1922, when modern instruments were developed. The term, coined in 1738 by W. Porterfield to describe his Scheiner slit optometer, and used for 200 years to describe many different inventions to measure refractive error of the eye, has completely fallen out of usage today as the task of measuring eyes for spectacles is done with modern instruments, such as the phoropter.
Usage examples of "optometer".
An optometer is an instrument for measuring refractive errors in eyes-in order that corrective lenses may be prescribed.