A unit of measure of the power of a lens or mirror, equal to the reciprocal of its focal length in meters. Myopia is diagnosed and measured in diopters
A measure of the optical image forming power of a lens and equal to the index of refraction of the medium in which the image is formed multiplied by the reciprocal of the focal length of the lens expressed in meters (The Science of Color)
A unit of measurement used by eye doctors and opticians to communicate the degree of refractive error with respect to nearsightedness, farsightedness, and astigmatism
A diopter is a unit of measure for expressing the magnifying power of a lens or lens system A one diopter lens has a focal distance of one meter A two diopter lens has a focal distance of one-half meter
a unit of measurement of the refractive power of a lens which is equal to the reciprocal of the focal length measured in meters
the measurement of refractive error A negative diopter value signifies an eye with myopia and positive diopter value signifies an eye with hyperopia
the unit of refracting power of lenses, denoting the reciprocal of the focal length expressed in meters
(dy-ahp-tur) A measurement of the degree to which light converges or diverges; also of lens refractive power Equal to the reciprocal of the focal length of a lens (in meters), e g , a 2-diopter lens brings parallel rays of light to a focus at half a meter Back to Top
unit of measurement that describes the refractive (light-bending) power of a lens and is used in prescriptions A negative value indicates a correction for nearsightedness (myopia), while a positive value indicates a correction for farsightedness (hyperopia)
A unit of measure of the refractive power of a lens, equal to the power of a lens with focal distance of one meter
A unit of measure of the refractive power if a lens A one-diopter lens will focus parallel light rays one meter from the lens and a two-diopter lens will focus one-half of a meter from the lens A plus 1 0 diopter lens is convex and will converge the light rays so they focus as a visible image 1 meter past the lens A minus 1 0 diopter lens is concave and will diverge or spread light The minus lens will not actually focus as a visible image on an optics table Its image is known as a virtual image and if the diverging rays were followed to their point of origin, they would focus one meter in front of the minus lens
the measurement of refractive error When used in excimer refractive surgery, diopter is a measurement of the refreactive power of the eye In LASIK and other refractive procedures, a negative diopter value signifies an eye with myopia and positive diopter value signifies an eye with hyperopia
An optician's term to describe the power of a lens In photography, it mainly indicates the magnifying power and focal length of a supplementary close-up lens
The diopter is the unit of measurement for optical lenses A one diopter lens will focus parallel light rays 1 meter from the lens and a two diopter lens will focus 0 5 meter from the lens A plus ( + ) 1 0 diopter lens is convex and will converge the light rays so they focus as a visible image 1 meter past the lens A minus ( - ) 1 0 diopter lens is concave and will diverge or spread light The minus lens will not actually focus as a visible image on an optics table Its image is known as a virtual image and if the divergings rays were followed to their point of origin they would focus 1 meter in front of the minus lens
a unit measurement of the degree to which light converges or diverges; Diopters are used to define of lens's refractive power Equal to the reciprocal of the focal length of a lens (in meters), e g , a 2-diopter lens brings parallel rays of light to a focus at half a meter
An optical instrument, invented by Hipparchus, for taking altitudes, leveling, etc
the unit of power (strength) for a lens; the reciprocal of the focal length, in meters (see equation 23 1)
Unit used to measure the amount of correction in your glasses or contact lens (nearshightedness, farsightedness and astigmatism)
Unit sometimes used to denote the light-bending power of a close-up lens The diopter value is the number of times its focal length will divide into one meter
A measurement of the degree to which light converges or diverges; also of lens refractive power Equal to the reciprocal of the focal length of a lens (in meters), e g , a 2- diopter lens brings parallel rays of light to a focus at half a meter
The part of the eyepiece on the camera that must be focused based on each individual's eyesight There are lines in a film camera and numbers in a video camera that can be used to focus the diopter If the diopter is not focused, the image through the camera will appear focused to the operators eye but what is being recorded will appear out of focus on screen to a different set of eyes
(D), unit of measure for the ability of a lens to alter the direction of a ray of light; 1 diopter will alter a ray of light 1 centimeter over a distance of 1 meter; 4 diopters (D) equals 1 power of magnification (X)
A measurement of the degree to which light converges or diverges; also of lens refractive power Equal to the reciprocal of the focal length of a lens (in meters), e g , a 2-diopter lens brings parallel rays of light to a focus at half a meter
An opticians term to describe the power of a lens In photography, it mainly indicates the magnifying power and focal length of a supplementary close-up lens
a unit of measure of the refractive power of a lens or of an eye, where the dioptric power is the inverse (reciprocal) of the focal length of the lens or of the eye's optical system in meters; a +1 00 D convex lens focuses light, from an infinite source, 1 ÷ 1 00 D = 1 meter away from the lens (and corrects an eye which is 1 00 D hyperopic); a +2 00 D lens focuses infinite light 1 ÷ 2 00 D = ½ meter away (and corrects an eye which is 2 00 D hyperopic); a +0 25 D lens focuses infinite light 1 ÷ 0 25 D = 4 meters away (and corrects an eye which is 0 25 D hyperopic); etc
() From French dioptre, from Latin dioptra or Greek διοπτρα (“to see through”).The Compact Edition of the Oxford English Dictionary, Oxford University Press, 1971