diopters
Optical power units
Diopters are units measuring the optical power of a lens or curved mirror—the inverse of the focal length in meters.
A lens that focuses light at one meter has a power of one diopter.
Eyeglass prescriptions use diopters to specify correction strength: My prescription is minus three diopters.
Higher numbers indicate stronger lenses.
Also spelled dioptres in British English.
Corrective lenses worn
- spectaclesCorrective eyewear worn daily
- bifocalLens with two focal lengths
- trifocalLens with three focal lengths
- progressiveFavoring reform and innovation
polycarbonate · photochromic · antireflective · curvature · refraction · optical · thickness · power
Blurry distance vision
- hyperopiaDifficulty seeing nearby objects
- astigmatismIrregular corneal curvature disorder
- presbyopiaAge-related near vision loss
- nearsightednessDefective distant vision
farsightedness · correction · spherical · cylinder · axis · prism · plus · minus
Standard measures of quantity
- scaleMeasure of relative size
- calibrationAdjusting for measurement accuracy
- graduationCompleting academic requirements formally
- incrementUnit of increase
wavefront · topography · quantify · gauge · precision · metric · conversion · chart
eyeglasses
Corrective lenses worn
- spectaclesCorrective eyewear worn daily
- bifocalLens with two focal lengths
- trifocalLens with three focal lengths
progressive · polycarbonate · photochromic · antireflective · curvature · refraction · optical · thickness · power · magnification
myopia
Blurry distance vision
- hyperopiaDifficulty seeing nearby objects
- astigmatismIrregular corneal curvature disorder
- presbyopiaAge-related near vision loss
nearsightedness · farsightedness · correction · spherical · cylinder · axis · prism · plus · minus · overcorrection
units
Standard measures of quantity
- scaleMeasure of relative size
- calibrationAdjusting for measurement accuracy
- graduationCompleting academic requirements formally
increment · wavefront · topography · quantify · gauge · precision · metric · conversion · chart
- opticslens, lenses, mirror, mirrors, prism
- vision correctionglasses, eyeglasses, contact lenses, contacts, LASIK