diopter
noun
di·op·ter
dī-ˈäp-tər 
ˈdī-ˌäp-
: a unit of measurement of the refractive power of lenses equal to the reciprocal of the focal length in meters
Examples of diopter in a Sentence
Recent Examples on the Web
Our tester found the twist-out eyecups and diopter worked well, but the objective lens caps were a tight fit.
—
Scott Gilbertson, WIRED, 6 Oct. 2024
Current Clinical Trials and Outcomes Clinical trials have started on the effectiveness of spiral diopter lenses for correcting presbyopia.
—William A. Haseltine, Forbes, 26 Feb. 2024
Most of the visual effects, in terms of the clairvoyance, were done in camera with me and a diopter, making a lot of noise and smashing glass against glass and a flashlight.
—Simon Thompson, Forbes, 13 Feb. 2024
While keeping the left side covered, rotate the diopter dial on the right eyecup until the image is in focus.
—Katherine Alex Beaven, Travel + Leisure, 17 Jan. 2024
Ophthalmologists measure this distortion in diopters, which refer to the strength of the lens required to bring someone’s vision back to normal.
—Amit Katwala, WIRED, 22 Aug. 2023
Take note of different arm heights, the number of nose bridges included, and whether or not there is built-in diopter tuning for nearsightedness.
—Hunter Fenollol, Popular Mechanics, 20 June 2023
The non-locking diopter is a tad too loose, and the finish is a little slick—both minor quibbles.
—Dave Hurteau, Field & Stream, 10 May 2023
With the exception of a slightly loose, non-locking diopter dial, everything feels smooth and positive and well-finished.
—Dave Hurteau, Field & Stream, 10 May 2023
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Scott Gilbertson, WIRED, 6 Oct. 2024
Current Clinical Trials and Outcomes Clinical trials have started on the effectiveness of spiral diopter lenses for correcting presbyopia.
—William A. Haseltine, Forbes, 26 Feb. 2024
Most of the visual effects, in terms of the clairvoyance, were done in camera with me and a diopter, making a lot of noise and smashing glass against glass and a flashlight.
—Simon Thompson, Forbes, 13 Feb. 2024
While keeping the left side covered, rotate the diopter dial on the right eyecup until the image is in focus.
—Katherine Alex Beaven, Travel + Leisure, 17 Jan. 2024
Ophthalmologists measure this distortion in diopters, which refer to the strength of the lens required to bring someone’s vision back to normal.
—Amit Katwala, WIRED, 22 Aug. 2023
Take note of different arm heights, the number of nose bridges included, and whether or not there is built-in diopter tuning for nearsightedness.
—Hunter Fenollol, Popular Mechanics, 20 June 2023
The non-locking diopter is a tad too loose, and the finish is a little slick—both minor quibbles.
—Dave Hurteau, Field & Stream, 10 May 2023
With the exception of a slightly loose, non-locking diopter dial, everything feels smooth and positive and well-finished.
—Dave Hurteau, Field & Stream, 10 May 2023
Cite this Entry
“Diopter.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/diopter. Accessed 30 Jun. 2025.
Copy CitationMedical Definition
diopter
noun
di·op·ter
variants
or chiefly British dioptre
: a unit of measurement of the refractive power of a lens equal to the reciprocal of the focal length in meters
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