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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 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 ...
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 .
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 ...
Uveitis. Uveitis ( / ˌjuːvi.aɪtɪs /) is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. [1] The uvea consists of the middle layer of pigmented vascular structures of the eye and includes the iris, ciliary body, and choroid.