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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 ...
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.
There are many diseases known to cause ocular or visual changes. Diabetes , for example, is the leading cause of new cases of blindness in those aged 20–74, with ocular manifestations such as diabetic retinopathy and macular edema affecting up to 80% of those who have had the disease for 15 years or more.
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 ...
An eponymous disease is a disease, disorder, condition, or syndrome named after a person, usually the physician or other health care professional who first identified the disease; less commonly, a patient who had the disease; rarely, a fictional character who exhibited signs of the disease or an actor or subject of a literary allusion, as characteristics associated with them were suggestive of ...
In optics, the Abbe sine condition is a condition that must be fulfilled by a lens or other optical system in order for it to produce sharp images of off-axis as well as on-axis objects. It was formulated by Ernst Abbe in the context of microscopes. [ 1] The Abbe sine condition says that. the sine of the object-space angle should be ...
H15-H22 Disorders of sclera, cornea, iris and ciliary body. (H15.0) Scleritis — a painful inflammation of the sclera. (H16) Keratitis — inflammation of the cornea. (H16.0) Corneal ulcer / Corneal abrasion — loss of the surface epithelial layer of the eye's cornea. (H16.1) Snow blindness / Arc eye — a painful condition caused by exposure ...
Convergence insufficiency. Convergence Insufficiency. Other names. Convergence disorder. Specialty. Ophthalmology, optometry. Convergence insufficiency is a sensory and neuromuscular anomaly of the binocular vision system, characterized by a reduced ability of the eyes to turn towards each other, or sustain convergence .