Definition of diopter
: a unit of measurement of the refractive power of lenses equal to the reciprocal of the focal length in meters
From the M-W Editors
Origin and Etymology of diopter
diopter (an optical instrument), from Middle French dioptre, from Latin dioptra, from Greek, from dia- + opsesthai to be going to see — more at optic
First Known Use: circa 1864
Medical Dictionary
diopter
noun
di·op·ter
Medical Definition of diopter
: a unit of measurement of the refractive power of a lens equal to the reciprocal of the focal length in meters
Learn More about diopter
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Britannica.com: Encyclopedia article about diopter
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