what is a lens
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lens 3. A thin piece of glass or plastic, as on a pair of sunglasses, that transmits light without refraction. 4. A device or phenomenon (such as a gravitational field) that causes light or other radiation to converge or diverge by an action analogous to that of a lens. 5.
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Lenses The focal length of a lens is the distance from the center of the lens to the point at which it focuses light rays. The shorter the focal length, the more powerful the lens. (It's easy to see why: an ordinary piece of glass would be like a lens of infinite focal length and wouldn't bring light rays to a focus at all.
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What are Progressive lenses? What are Progressive lenses? A progressive lens is an amazing piece of engineering, allowing multiple vision fields to be incorporated into a single lens without any clear distinction between the fields themselves. The power in the lenses progressively changes from far-to intermediate to your full reading power.
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glasses glasses - optical instrument consisting of a frame that holds a pair of lenses for correcting defective vision. eyeglasses, specs, spectacles. bifocals - eyeglasses having two focal lengths, one for near vision and the other for far vision. nosepiece, bridge - the link between two lenses; rests on the nose.
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- Ruminants use NPN by converting it via the ruminal microflora to ammonia, which is then combined with carbohydrate-derived keto acids to form amino acids. The most common sources of NPN in feeds are urea, urea phosphate, ammonia (anhydrous), and salts such as monoammonium and diammonium phosphate. Because feed-grade urea is unstable, it is formulated (usually pelleted) to prevent degradation to NH3.
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- ( lenses plural ) 1 n-count A lens is a thin curved piece of glass or plastic used in things such as cameras, telescopes, and pairs of glasses. You look through a lens in order to make things look larger, smaller, or clearer. ...a camera lens..., I packed your sunglasses with the green lenses.
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- Converging lenses A lens is transparent block that causes light to refract (changes the direction the light travels in). A converging lens (or convex lens) is curved on both sides.
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- A scleral lens is a specialized contact lens used to manage a variety of eye conditions. It is made of plastic that is clear and rigid, yet allows the eye to breathe, keeping it healthy. A scleral lens is slightly larger than most soft contact lenses and is designed to rest on the white (less sensitive) part of the eye called the sclera. That is why it’s called a scleral lens! This unique design makes the lens very comfortable to wear, all day long.
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- Definition of Convex Lens. A lens which is thinner at the edges and thicker at the centre is known as convex lens. Generally lenses are made up of glass or transparent plastic and the same can be used for transmitting, refracting or for focusing the light.
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Lens The lens is located in the eye. By changing its shape, the lens changes the focal distance of the eye. In other words, it focuses the light rays that pass through it (and onto the retina) in order to create clear images of objects that are positioned at various distances.
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- Glasses (Definition) 1  Glasses is a term that describes a pair of lenses that are placed in a frame to be worn to correct faulty vision or protect the eyes. ...Read more. 2  Eye wear is a device that either improves vision or protects the eyes from dangerous materials. ...Read more.
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Plural Nouns Examples Help - Some helpful rules. There are some rules when working with English plurals: 1  Just add an 's' to make most words plural - examples: cats, dogs, girls, bats.  If the noun ends with a ch, s, sh, x, or z add an 'es' to make it plural - examples: churches, boxes, witches, witnesses.
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Lens (optics) Lens (optics) - Imaging properties. 1  As mentioned above, a positive or converging lens in air focuses a collimated beam travelling along the lens axis to a spot (known as the focal point) at a distance f from the lens.
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Pupil The pupil is a hole located in the centre of the iris of the eye that allows light to strike the retina. It appears black because light rays entering the pupil are either absorbed by the tissues inside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil.
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- Lenses definition, a piece of transparent substance, usually glass, having two opposite surfaces either both curved or one curved and one plane, used in an optical device in changing the convergence of light rays, as for magnification, or in correcting defects of vision. See more.
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- Touch Power off OK. Setting Up for the First Time When you first power on your phone after you purchase it or reset it to factory settings (see Settings – Personal – Backup and Reset), follow the onscreen instructions to set it up.1.onfigure the Google location options and touch Next .4. Enter your name which the phone uses to personalize some apps and touch Next .5. Touch Finish to complete the setup. NOTE: If the phone cannot connect to a mobile network, it would prompt you to connect to a Wi-Fi network.
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lens lens (lěnz) n. pl. lens·es A ground or molded piece of glass, plastic, or other transparent material with opposite surfaces either or both of which are curved, by means of which light rays are refracted so that they converge or diverge to form an image.
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- More About Convex Lens. 1  A convex lens is supposed to be made up of number of prisms with the base of each prism towards the centre of the lens. 2  When rays parallel to the principal axis pass through a convex lens, they are bent inwards.  The point at which they converge is known as principle focus.
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Lens (optics) Lens (optics) 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.
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What is the definition of a âprime lensâ? A prime lens is a lens which does not zoom. That is, as you say, it has a fixed focal length. All lens design is a matter of balancing competing factors, including various optical properties which affect image quality in different ways, as well as size, weight, and cost.
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The Canon Lens Experience: Everything You Need to Know about Canon Lenses But even in its most basic form, a camera lens is far more complex than it might appear. A lens is more than the sum of its parts. When you attach a lens to a camera, your choice of lens is very much like a painter's choice of brush. For finer details, the painter will choose a narrow, pointier brush. For cloud-free skies, a broader brush would be a wiser choice.
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Pupil (eye) Pupil (eye) The pupil is the opening in the centre of the eye. Light enters through the pupil and goes through the lens, which focuses the image on the retina. The size of the pupil is controlled by muscles. There is a circular group, which squeezes the iris smaller, and another group which pulls the iris wider. When more light is needed, the pupil is made larger. In brighter light, the pupil is made smaller.
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lens Any lens that is not of curved form. 2. A contact lens in which the back optic zone radius is longer than the flattest meridian of the cornea. This definition may not be valid for a soft lens that may have a back optic zone radius longer than the flattest meridian of the cornea and yet not be flat fitting.. crystalline lens; the transparent, biconvex body separating the posterior chamber and the vitreous body of the eye. The crystalline lens refracts (bends) light rays so that they are focused on the retina.
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lens A combination of two or more such pieces, sometimes with other optical devices such as prisms, used to form an image for viewing or photographing. Also called compound lens. 3. A thin piece of glass or plastic, as on a pair of sunglasses, that transmits light without refraction. 4. A device or phenomenon (such as a gravitational field) that causes light or other radiation to converge or diverge by an action analogous to that of a lens.
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Zoom lens For the American record label, see Zoom Lens (record label). A zoom lens is a mechanical assembly of lens elements for which the focal length (and thus angle of view) can be varied, as opposed to a fixed focal length (FFL) lens (see prime lens).
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Spherical Lenses Lens lentis is the Latin word for lentil. It's good word for English speakers since few of us associate lenses with lentils and not all lenses are lentil shaped. What makes a lens different from any other transparent object is its ability to focus light. A focus is a meeting point.