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  2. Levelling - Wikipedia

    en.wikipedia.org/wiki/Levelling

    Levelling or leveling ( American English; see spelling differences) is a branch of surveying, the object of which is to establish or verify or measure the height of specified points relative to a datum. It is widely used in geodesy and cartography to measure vertical position with respect to a vertical datum, and in construction to measure ...

  3. Subjective refraction - Wikipedia

    en.wikipedia.org/wiki/Subjective_refraction

    Subjective Refraction is a technique to determine the combination of lenses that will provide the best corrected visual acuity (BCVA). [1] It is a clinical examination used by orthoptists, optometrists and ophthalmologists to determine a patient's need for refractive correction, in the form of glasses or contact lenses.

  4. Ophthalmic trial frame - Wikipedia

    en.wikipedia.org/wiki/Ophthalmic_trial_frame

    ophthalmic trial frame is used to hold lenses and other accessories during correction of refractive errors. Test of. Visual acuity. A trial frame is a tool used by ophthalmic professionals like ophthalmologists and optometrists. It is basically an adjustable spectacle frame with multiple cells, used to hold corrective lenses, and other ...

  5. Lens - Wikipedia

    en.wikipedia.org/wiki/Lens

    A lens is a transmissive optical device that focuses or disperses a light beam by means of refraction. A simple lens consists of a single piece of transparent material, while a compound lens consists of several simple lenses ( elements ), usually arranged along a common axis.

  6. Optical coating - Wikipedia

    en.wikipedia.org/wiki/Optical_coating

    Optical coating. An optical coating is one or more thin layers of material deposited on an optical component such as a lens, prism or mirror, which alters the way in which the optic reflects and transmits light. These coatings have become a key technology in the field of optics. One type of optical coating is an anti-reflective coating, which ...

  7. Human eye - Wikipedia

    en.wikipedia.org/wiki/Human_eye

    The human eye is an organ of the sensory nervous system that reacts to visible light and allows the use of visual information for various purposes including seeing things, keeping balance, and maintaining circadian rhythm . Arizona Eye Model. "A" is accommodation in diopters. The eye can be considered as a living optical device.

  8. Time base correction - Wikipedia

    en.wikipedia.org/wiki/Time_base_correction

    Time base correction (TBC) is a technique to reduce or eliminate errors caused by mechanical instability present in analog recordings on mechanical media. Without time base correction, a signal from a videotape recorder (VTR) or videocassette recorder (VCR), cannot be mixed with other, more time-stable devices found in television studios and ...

  9. Category:Optometry - Wikipedia

    en.wikipedia.org/wiki/Category:Optometry

    A. Accommodation (vertebrate eye) Accommodative infacility. American Academy of Optometry. American Society of Cataract and Refractive Surgery.