Ads
related to: bifocals wikipedia english
Search results
Results From The WOW.Com Content Network
A method for fusing the sections of the lenses together was developed by Louis de Wecker at the end of the 19th century and patented by John Louis Borsch Jr. (1873–1929) [9] in 1908. Today most bifocals are created by molding a reading segment into a primary lens and are available with the reading segments in a variety of shapes and sizes.
Progressive lenses are corrective lenses used in eyeglasses to correct presbyopia and other disorders of accommodation. They are characterised by a gradient of increasing lens power, added to the wearer's correction for the other refractive errors. The gradient starts at the wearer's distance prescription at the top of the lens and reaches a ...
Glasses. Glasses, also known as eyeglasses and spectacles, are vision eyewear with clear or tinted lenses mounted in a frame that holds them in front of a person's eyes, typically utilizing a bridge over the nose and hinged arms, known as temples or temple pieces, that rest over the ears. Glasses are typically used for vision correction, such ...
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.
Adjustable focus eyeglasses are eyeglasses with an adjustable focal length. They compensate for refractive errors (such as presbyopia) by providing variable focusing, allowing users to adjust them for desired distance or prescription, or both. Current bifocals and progressive lenses are static, in that the user has to change their eye position ...
Bioptics (device) Bioptics, also known as a bioptic in the singular, and sometimes more formally termed a bioptic telescope, is a term for a pair of vision -enhancement lenses. They magnify between two and six times, and are used to improve distance vision for those with severely impaired eyesight, especially those with albinism.
A burning apparatus consisting of two biconvex 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.
Contact lens. A pair of contact lenses, positioned with the concave side facing upward. Putting contacts in and taking them out. One-day disposable contact lenses with blue handling tint in blister-pack packaging. Contact lenses, or simply contacts, are thin lenses placed directly on the surface of the eyes. Contact lenses are ocular prosthetic ...
Ads
related to: bifocals wikipedia english