|Spectacle lenses-materials development(2)|
(Iii) Characteristics of optical glass and defects
Glasses should have the following characteristics:
1. Homogeneity (homogeneity of chemical composition and physical state) if the lens material fracture, deformation of bubbles and impurities, turbidity, etc, you will seriously affect the optical properties.
2. Suitable refractive index and dispersion of refractive index with wavelength values decline and increase in refractive index higher dispersion normally has gradually increased. For example, refractive index of optical glass to 1.8, Abe number 32~35.4, patients often complain when wearing Ray Ban Outlet
sunglasses disturbances of the Visual color stripes. Refractive index increases usually share also increased so high refractive index lens thickness is thin, but the weight is heavier.
3. High transparency optical transmittance as 92%, high refractive index glass transmittance decrease due to reflecting increased and, in addition, lenses thicker due to light absorption, light transmission rate would also be reduced.
4. Chemical and physical stability of optical glass can be effective and durable resist weather effects, and does not stain or fade. Dual light microscope, tablets and tablets should have the same expansion rate.
(D) The hardness of glass
Theoretical tensile strength of optical glass is very high, more than 4 million pounds per square inch, but in fact was 2000~10000 pounds per square inch when the rupture occurred, Cheap Ray Ban Sunglasses
and optical non-ductile, brittle high. Impact resistance of glass depends on its surface and edge quality. United States FDA on lens strength standards of strict rules, to minimize or avert a serious eye injury when lens broken.
(E) The glass gradually superseded by resin
With the growing development of science and technology, ophthalmology, optical, manufacturing processes as well as increasingly sophisticated, in-depth knowledge, and receptors of the eye as a receive optical information suffered light damage increasingly being recognized, UV light is only 5% of the solar radiation energy, but the worst eye. The refractive media eye absorbs most of the ultraviolet light, but there is still a small part of the ultraviolet light reach the retina, retinal phonic injury leading to chronic. Therefore, glasses as the correction of refractive errors, other medical tools, the ideal lens not only to have perfect optical performance, light weight, thin, and must have absorbed ultraviolet light, sufficient impact resistance and so on. Glass as a Cheap Ray Bans
weary lens material has overcome many disadvantages, therefore, the current market share has been declining, and resin lens came into being.
|7 Gas welding goggles|
The Ray Ban Outlet lenses colorants used mainly for iron oxide, cobalt oxide, yellow green, NM or less can absorb all wavelengths of visible light transmittance of less than 1%, only a small amount of current through the infrared. This eye designed for use when welding gas welding operation.
8 welding with goggles
Welding produces ultraviolet light, short-term exposure can cause the eye cornea and conjunctiva tissue damage (to 28nm light most severe). Generated intense infrared easily cause eye lens capacities. Welding goggles can be well above intercept infrared and ultraviolet. This lens with optical glass based on the use of iron oxide and cobalt oxide colorants, in addition to a certain amount of cerium oxide to increase the absorption of ultraviolet light, the appearance of green or yellow green. Can all block ultraviolet rays, infrared rays, infrared transmittance of <5%, visible light transmittance of about 0.1%.
9 blue goggles
This Cheap Ray Ban Sunglasses, there are two, one for iron oxide and cobalt oxide coloring, use it to see the filament is purple, the other is a copper oxide, manganese oxide coloring, use it to see the filament is white. They can absorb all 500 ~ 600nm (visible light sensitive eye area) band dazzling glare, light transmittance at 400nm at below 12%, there is a certain UV absorption, suitable for various industrial furnace blast furnace operation personnel wear.
10 dark red glass glasses
This is a kind of spectacle lenses using cadmium sulfide, cadmium serenade sulfur crimson colored glass, it can absorb at 600nm wavelength light all of the following bands.
11 laser protective weary
This Cheap Ray Bans glasses two forms, reflective and absorption, the former plated surface using vacuum coating a metal film, wavelengths of 532nm, 694nm and 1060nm, such as laser wavelength is greater than the reflectance of 99.5%; the latter lens for 1060nm wavelength laser can all be absorbed. Lenses must be accompanied enclosed or semi-enclosed frame around the lens to prevent the laser injected into the eye.
|Ray Ban Outlet glasses, that is for vision correction or eye protection lenses. It is both eye protection products, but also when a cosmetic decorations.|
Now, more and more varieties of glasses, classification is also getting smaller. In addition to glasses, reading glasses, sunglasses, also including the driver safety glasses, computer safety glasses, goggles and other leisure and sports goggles for special industries, working and recreation special glasses varieties. Also, to promote the progress of the times that people consume the heart of maturity. Consumers pay more attention to product diversification, personalization. The demand for glasses vision care from a single rose to the level of cultural, aesthetic and other three-dimensional consumer space, which will stimulate new varieties of new styles of glasses, research, development and sales, retail glasses bring development to a new opportunity.
With Amy to the increasing demand for eyeglasses, sunglasses myopia has begun combining beautiful nature, with many new products come out. Contact lenses to join, in terms of myopia can be called by a supplement. Contact lenses popular and its ample reason: it eliminates the hassle of glasses, does not affect the appearance, look more three-dimensional sense objects.
"Contact lens" is a small and thin synthetic plastic lenses, placed on the cornea. Its main objectives are: correction of refractive error, corneal disease treatment, beauty, as well as the convenience of job or career (such as athletes, microscope or camera users).
Recently, color stealth Cheap Ray Ban Sunglasses have begun approaching the general population, it can not only improve vision, but also allows the wearer can according to their preferences change eye color, beauty who greatly to meet the demand. Moreover, UV contact lenses are also very popular place, because contact lenses glasses did not like the UV reflection, absorption and scattering, but outsiders to accurately focus light on the eye, which may lead to invasion of UV on the eye. Currently on the market place to UV contact lenses, blocking 95% of ultraviolet rays to reach ground level, it can greatly avoid the UV on the eye to violations.
2 reading glasses
Currently, with reading glasses to prescription, there are two: one is close objects clearly spectacles, plus 1/3 degrees to adjust; another one is able to see close objects using the minimum degree of. After many older people proved that the latter of these two methods is better.
We often saw on television many foreign heads of state, politicians, academics, speech on the stage, wearing a pair of glasses, both to look too far and can see the past. This is because they wear multifunctional glasses - progressive multiform glasses. Progressive multiform lens prescription is to look too far, fancy, look past the desired refractive lens to focus on the same form multiple focal glasses, wear it both to see distant objects, but also to the distance operate a computer, but also close to read and write. Currently in Europe, Japan, the United States and other older age groups, the use of progressive multiform lenses high percentage of people, and is widely replace bifocal Cheap Ray Bans glasses, single optical glasses. Progressive multiform glasses for the elderly because it can provide a comprehensive vision of freedom, and the wide field of vision, adapt to rapid, easy to use, beautiful appearance, has been loved by more and more customers. Buy a pair of reading glasses have become the past, with a progressive multiform glasses in the elderly is the modern manifestation of visual requirements for high quality, high taste of life choices.
|Read a glasses prescription|
|Following simple instructions about thumbnail symbols in prescription Ray Ban Outlet glasses:|
(1) glasses degrees of said law: s: said spherical lens, (-) Si myopia, with (+) Si hypertrophy, and old depending on with; c: said column surface lens, astigmatism Si using; DS: to mark spherical lens of light Coke degrees; DC: to mark column surface lens of light Coke degrees; AX: (AXIS) shows column mirror axis, astigmatism axis to is to column axis and horizontal lines by into angle for standard, its marked method currently used of is TABO marked law. Horizontal degrees to 0 ° and 180 °, the degree symbol "°" can be omitted.
(2) The representation p Cheap Ray Ban Sunglasses Prism: Prism: Prism unit b Prism base, BI: basement (basement near the nose), BO: out of the basement (basement near the temporal), BU: base bottom up, BD: basement down.
(3) Other: PD: pupil distance, Add: join, dual light microscope, OD/RE/r for right eye, OS represent left eye or LE, or l, OU, or BE representative of both eyes.
Cheap Ray Bans glasses prescriptions written for example: R:-2.50/-2.00DCx95 or (-2.50/-2. 00x95) or L:-2.00/-1.50DCx85 (-2.00/-1.50x.85) PD: 63mm
Explain prescription right eye above 250 degrees of myopia with astigmatism of-200, on 95 degree astigmatism axial, left eye of 200-150 degrees of myopia astigmatism, astigmatism axial on an 85 degree, interplanetary distance is 63 mm.
|Vice-suited for their election glasses|
|In fact, as long as the election of the stylish and compact Ray Ban Outlet sunglasses, matched with glasses harmony "glasses" make-up, the same can distribute unique charm.|
1, tough gusto - blue narrow-rimmed glasses
If your style cool, but also a palm-sized little face, then these blue narrow-rimmed glasses will definitely help you win 100% of the heads. Founder of the human face shape as long as the size of the frame to pay more attention, the same can wear out the valiant feeling.
2, Fashion gusto - large-framed glasses
Almost half of the face covering large-framed glasses gives people a sense of mystery, people kind of wait to see the face of the impulse glasses. Long shaped face for wearing large-framed glasses, the choice of colors can be freely, gold is more popular this year, color, bold fashion girl can try.
3, the smaller thin - metal glasses
Looks sweet, shy girl may be more suitable metallic glasses, metal glasses on the market now are very light, to maximize ease the burden on the nose. Any person can face shape bold attempt metals Cheap Ray Ban Sunglasses, show your introverted side.
"Glasses" makeup tips
Elected to their favorite glasses, you can start of "glasses" makeup, the makeup different from ordinary, "glasses" more emphasis on the eye contour makeup.
Cheap Ray Bans glasses wearing myopic people, glasses lenses easily become small, so use brightly colored pearl eye shadow rendering, highlighting the eye contour, carefully painted the roots of eyelashes with eyeliner, eyelash curler and then fully curling eyelashes, finally type with thick mascara, so the eyes will become more vivid.
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