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Abbe number. In optics and lens design, the Abbe number, also known as the V-number or constringence of a transparent material, is an approximate measure of the material's dispersion (change of refractive index versus wavelength), with high values of V indicating low dispersion. It is named after Ernst Abbe (1840–1905), the German physicist ...
Clear lens extraction, also known as refractive lensectomy, custom lens replacement or refractive lens exchange is a surgical procedure in which clear lens of the human eye is removed. Unlike cataract surgery , where cloudy lens is removed to treat cataract , clear lens extraction is done to surgically correct refractive errors such as high ...
Corrective lens. A corrective lens is a transmissive optical device that is worn on the eye to improve visual perception. The most common use is to treat refractive errors: myopia, hypermetropia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short distance in front of the eye.
An optical instrument is said to be diffraction-limited if it has reached this limit of resolution performance. Other factors may affect an optical system's performance, such as lens imperfections or aberrations, but these are caused by errors in the manufacture or calculation of a lens, whereas the diffraction limit is the maximum resolution ...
2325-8179 (web) OCLC no. 820959361. Links. Journal homepage. Online archive. Ophthalmic Surgery, Lasers and Imaging Retina is a monthly peer-reviewed medical journal of ophthalmology covering retinal diseases, surgery, and pharmacotherapy. It was established in 1970 and is published by SLACK Incorporated. [1]
A patient in front of a tonometer. Intraocular pressure ( IOP) is the fluid pressure inside the eye. Tonometry is the method eye care professionals use to determine this. IOP is an important aspect in the evaluation of patients at risk of glaucoma. [ 1] Most tonometers are calibrated to measure pressure in millimeters of mercury ( mmHg ).
Third Eye Diagnostics, Inc. is developing the Cerepress™, a non-invasive, hand-held intracranial pressure monitor that gathers information from the patient's un-dilated eye. The Cerepress™ measures blood pressure in the eye's central retinal vein (CRV) and blood velocity in the ophthalmic artery, which taken together highly correlate to ...
Chromatic aberration. Focal length of lens varies with the color of light. In optics, chromatic aberration ( CA ), also called chromatic distortion, color aberration, color fringing, or purple fringing, is a failure of a lens to focus all colors to the same point. [ 1][ 2] It is caused by dispersion: the refractive index of the lens elements ...