Definition

Noun: - A unit of measurement for the refractive power of a lens: A dioptre is a unit that quantifies the optical power of a lens or curved mirror. It is defined as the reciprocal of the focal length measured in meters. A lens with a power of one dioptre has a focal length of one meter.

Usage

• The dioptre is the standard unit used by optometrists, ophthalmologists, and optical engineers to prescribe and describe the corrective power of eyeglasses and contact lenses.
• It is used to express both positive power (for converging lenses that correct farsightedness) and negative power (for diverging lenses that correct nearsightedness).

Examples

Advanced Usage

• Dioptric power: This term refers specifically to the refractive power expressed in dioptres.
  • The dioptric power of the intraocular lens was calculated precisely.
• Dioptric adjustment: Refers to the mechanism on optical instruments (like microscopes or binoculars) that allows users to adjust for differences in eyesight.
  • Remember to use the dioptric adjustment ring to compensate for your vision.

Variants and Related Words

• Diopter (noun): The American English spelling of "dioptre".
• Dioptric (adjective): Pertaining to dioptres or refraction by lenses.
  • The dioptric system of the eye focuses light onto the retina.

Synonyms

• Refractive power unit: A descriptive synonym, though "dioptre" is the specific, standard term.

Related Phrases

(Note: "Dioptre" itself is a technical noun and does not form phrasal verbs or common idioms. Its usage is primarily in technical and medical contexts.)

Noun

1. a unit of measurement of the refractive power of a lens which is equal to the reciprocal of the focal length measured in meters; used by oculists