How many types of silicon hydrogel conact lenses are there, who makes them?
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There are three types.\nAccuvue makes them, a division of Johnsons and Johnson.
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Leonardo da Vinci is frequently credited with introducing the general principle of contact lenses in his 1508 Codex of the eye, Manual D, where he described a method of directly altering corneal power by submerging the eye in a bowl of water. \nRené Descartes proposed another idea in 1636, in which a glass-tube filled with liquid is placed in direct contact with the cornea. The protruding end was to be composed of clear glass, shaped to correct vision; however the idea was unworkable, since it would make blinking impossible.\n\nIn 1801, while conducting experiments concerning the mechanisms of accommodation, scientist Thomas Young constructed a liquid-filled "eyecup" which could be considered a predecessor to the contact lens. On the eyecup's base, Young fitted a microscope eyepiece. However, like da Vinci's, Young's device was not intended to correct refraction errors.\n\nSir John Herschel, in a footnote of the 1845 edition of the Encyclopedia Metropolitana, posed two ideas for the visual correction: the first "a spherical capsule of glass filled with animal jelly", and "a mould of the cornea" which could be impressed on "some sort of transparent medium". Though Herschel reportedly never tested these ideas, they were both later advanced by several independent inventors, seemingly unaware of Herschel's suggestion.\n\nIt was not until 1887 that the German physiologist Adolf Eugen Fick constructed and fitted the first successful contact lens. While working in Zürich, he described fabricating afocal scleral contact shells, which rested on the less sensitive rim of tissue around the cornea, and experimentally fitting them: initially on rabbits, then on himself, and lastly on a small group of volunteers. These lenses were made from heavy brown glass and were 18-21mm in diameter. Fick filled the empty space between cornea/callosity and glass with a grape sugar solution. He published his work, "Contactbrille", in the journal Archiv für Augenheilkunde in March 1888.\n\nFick's lens was large, unwieldy, and could only be worn for a few hours at a time. August Muller in Kiel, Germany, corrected his own severe myopia with a more convenient glass-blown scleral contact lens of his own manufacture in 1888.\n\nGlass-blown scleral lenses remained the only form of contact lens until the 1930s when polymethyl methacrylate (PMMA or Perspex/Plexiglas) was developed, allowing plastic scleral lenses to be manufactured for the first time. In 1936 an optometrist, Dr. William Feinbloom introduced plastic lenses, making them lighter and more convenient. These lenses were a combination, however, of both plastic and glass.\n\nIn the 1950s, the first 'corneal' lenses were developed--these were much smaller than the original scleral lenses, as they sat only on the cornea rather than across all of the visible ocular surface. PMMA corneal lenses became the first contact lenses to have mass appeal through the 1960s, as lens designs became more sophisticated with improving manufacturing (lathe) technology.
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Because the silicon chip inside is light sensitive, so they need opaque casings to keep from stray light from interfering with the proper operation of the device. Some light sensing chips are made with a clear epoxy body and a molded-in lens.
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use contact lens,I don't think there's any other way.
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José Ignacio Barraquer \nhttp://en.wikipedia.org/wiki/Lasik\nhttp://en.wikipedia.org/wiki/Jose_Barraquer\n\nThere are several other contributors listed under "Technology Development" in the Lasik wiki article.
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They tend to be specialize to specific types, but here is one:\nhttp://www.amctools.com/\nJust do a google search for more types
45448
What lens are you looking for? Have you tried the store pages in a photo mag? The sites you are checking can be some type of feeder pages but I don't know. If you post more info to your question or move it to the photgraphy section under Arts/Visual Arts/Photography you are sure to get some answers.
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eyelash, lash, cilium
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See  http://en.wikipedia.org/wiki/Lenticular_printing\n\nTh
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dude this is a great site. I got one of storms contact lenses from this site.
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http://www.perma-flex.com/sections/product/silicone.asp\n\nhope this helps
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Microslides, Concavity Slides, Cover Glasses, India, Manufacturers, Haryana, Shree Ganesh Scientific Industries, ... \n... standard white coating which offers alternative marking method to frosted slides. ... to the standard of BUREAU OF INDIAN STANDARDS & ISI. Slides' surfaces: ...\n72.29.26.73/products.htm\nhttp://72.29.26.73/products.htm
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The medium of a lens is the material which it is made of.
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for the size of the lens i would go back to the lens maker formula it is:\npower of lens = (n(lens) - n(0)) * (1/R1 - 1/R2)\nwhere n(lens) is refractive index of lens material\nn(0) is refractive index of the medium in which lens is kept\nR1 and R2 are surface radius of the two sides of the lens.\nso you can see from the equation to increase power of the lens we can either increase refractive index of the lens (assuming we are seeing it in air) or reduce the radius of curvature of the lens sides. so ideally as power increses the radius of the lens decreases and so the size of the lens also reduces. you can also check out gullstrands equation for further reference of thicker lenses. hope this helps
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Try gelest.com, they manufacture a LOT of Si compounds for many applications.
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I used to make contact lenses, I actually researched a page on this for my ex company. Leonardo da Vinci sketched and described several forms of contact lenses in 1508. You can read the page I researched for them below.
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1. a combinatoin of lens is made up of two simple lenses attached together. The lenses are made from glasses with different refractive indices and different amounts ot dispersion. This combination produces a better image than a simple lens. Most commercial doublets are achromats, which are optimized to reduce chromatic aberration while also reducing spherical aberration and other optical aberrations.\n2. i = r =  0\n3. 90\n4. >> Shaving  >> you should put the obiect between the focus and the mirror to have magnified and a virtual image.\n   >> Doctor's mirror >> light to be in the focus to have a parallel beam