It is unknown when the first spectacles were made. The British scientist and historian Sir Joseph Needham, in his Science and Civilization in China, discusses the occasional claim that spectacles were invented in China. He states that the belief may have been based on a source that was modified during the Ming dynasty (14th - 17th century), that the original document made no references to eyeglasses, and that the references that were there[which?] stated the eyeglasses were imported.[4]
Previously, testing the RemoveDEBRIS system has meant checking out its fundamentals—using a net to simulate a capture, using onboard LIDAR and optical camera systems to identify space junk. — David Grossman, Popular Mechanics, "Watch a Space Junk Harpoon Complete a Successful Test Shot," 15 Feb. 2019 Beyond that, the Command Bar comes with a nice variety of connectivity options: an HDMI-ARC port, two HDMI 2.0 inputs, an optical digital audio input, and Bluetooth support. — Jeff Dunn, Ars Technica, "The Ars Holiday Gift Guide 2018—good tech for the home and home office," 19 Nov. 2018 The Galaxy Note 9, similar to this year’s Galaxy S9, has impressive dual cameras on the back, a wide-angle and a 2X telephoto, both with optical image stabilization. — David Pierce, WSJ, "Samsung’s Galaxy Note 9 Is Crazy Powerful. Can You Handle It?," 19 Aug. 2018 Note that this particular model only accepts analog RCA and 3.5mm audio connections, however—optical inputs aren’t supported. — Alexandria Haslam, PCWorld, "Punch up your PC audio! Logitech's powerful Z623 speaker system is $80, its lowest price ever," 9 Aug. 2018 As in standard optical communications, a photon can be transmitted to a receiver—in this case, another diamond vacancy—and its quantum state transferred to a new electron, so the two electrons become correlated. — Neil Savage, Scientific American, "What Are the Limits of Manipulating Nature?," 8 May 2018 As the show’s 80 or so works, video slide shows and film clips demonstrate, rarely has an optical phenomenon threaded its way through so many aspects of modern culture, from mass-market fads to avant-garde art. — Susan Delson, WSJ, "In a Los Angeles Exhibition, 3-D in All Its Dimensions," 29 June 2018 Similar to sun dogs, lunar and solar halos belong to the family of ice halos, which are optical phenomena formed by the refraction of sun on hexagonal ice crystals suspended high up in the atmosphere, most commonly in cirrus clouds. — Kathryn Prociv, Washington Post, "Skywatchers in Chile were star-struck by this incredible lunar halo," 13 Apr. 2018 During the last decade, the space technology program has supported research into optical communications for communicating with deep space probes, environmental propellants, and nuclear thermal propulsion, among many other areas. — Eric Berger, Ars Technica, "In response to Trump budget, NASA ending separate technology plan," 1 Mar. 2018
When a ray of light emerges obliquely from glass into air, the angle of refraction between ray and normal is greater than the angle of incidence inside the glass, and at a sufficiently high obliquity the angle of refraction can actually reach 90°. In this case the emerging ray travels along the glass surface, and the sine of the angle of incidence inside the glass, known as the critical angle, is then equal to the reciprocal of the refractive index of the material. At angles of incidence greater than the critical angle, the ray never emerges, and total internal reflection occurs, for there is no measurable loss if the glass surface is perfectly clean. Dirt or dust on the surface can cause a small loss of energy by scattering some light into the air.
Our one-on-one approach to optometry makes the Jordan Vision Clinic staff the eye and vision care providers of choice in the West Jordan area. Our West Jordan optometrist offers the following services: complete eye exams, contact lenses, glasses, glaucoma testing, and pre- and post-operative care. For a complete list of services, visit our services page or call our West Jordan office at 801-561-2020.

Because the refractive index of glass varies with wavelength, every property of a lens that depends on its refractive index also varies with wavelength, including the focal length, the image distance, and the image magnification. The change of image distance with wavelength is known as chromatic aberration, and the variation of magnification with wavelength is known as chromatic difference of magnification, or lateral colour. Chromatic aberration can be eliminated by combining a strong lens of low-dispersion glass (crown) with a weaker lens made of high-dispersion (flint) glass. Such a combination is said to be achromatic. This method of removing chromatic aberration was discovered in 1729 by Chester Hall, an English inventor, and it was exploited vigorously in the late 18th century in numerous small telescopes. Chromatic variation of magnification can be eliminated by achromatizing all the components of a system or by making the system symmetrical about a central diaphragm. Both chromatic aberration and lateral colour are corrected in every high-grade optical system.


The apparent brightness of things seen by the eye follows the same laws as any other imaging system, because the apparent brightness is measured by the illuminance in the image that is projected on the retina. The angle U′ in equation (8) inside the eye is determined by the size of the pupil of the eye, which varies from about one millimetre to about eight millimetres, depending on the brightness of the environment. Apart from this variation, retinal illuminance is directly proportional to object luminance, and objects having the same luminance appear equally bright, no matter at what distance they are observed.

For those who need professional ophthalmology treatment, we have two operating suites in our office where we can perform surgical procedures on site such as LASIK, diabetic eye disease treatment, brow lifts, and blepharoplasties. As for intraocular surgeries for glaucoma or cataracts, we perform the surgeries at a local hospital so the care you need is never far from home. We also offer 24/7 emergency assistance so we can help you when you need us most. Just contact our emergency number at (801) 625-3039. 


Because the refractive index of glass varies with wavelength, every property of a lens that depends on its refractive index also varies with wavelength, including the focal length, the image distance, and the image magnification. The change of image distance with wavelength is known as chromatic aberration, and the variation of magnification with wavelength is known as chromatic difference of magnification, or lateral colour. Chromatic aberration can be eliminated by combining a strong lens of low-dispersion glass (crown) with a weaker lens made of high-dispersion (flint) glass. Such a combination is said to be achromatic. This method of removing chromatic aberration was discovered in 1729 by Chester Hall, an English inventor, and it was exploited vigorously in the late 18th century in numerous small telescopes. Chromatic variation of magnification can be eliminated by achromatizing all the components of a system or by making the system symmetrical about a central diaphragm. Both chromatic aberration and lateral colour are corrected in every high-grade optical system.
Many types of optical instruments form images by natural light, but some, such as microscopes and projectors, require a source of artificial light. Tungsten filament lamps are the most common, but if a very bright source is required, a carbon or xenon arc is employed. For some applications, mercury or other gas discharge tubes are used; a laser beam is often employed in scientific applications. Laser light is brilliant, monochromatic, collimated (the rays are parallel), and coherent (the waves are all in step with each other), any or all of these properties being of value in particular cases.
Over the years, the staff at Healthy Eyes for Life has kept up to date with the latest advancements and developments in eye care to ensure that we provide our patients with top quality care. From treatments for glaucoma, cataracts and corneal disease to advancements in prescription eyewear and contact lenses, we offer the most advanced eye care options in the West Jordan area.
To interpret these aberrations, the simplest procedure is to find the components x′, y′ of the displacement of a ray from the Lagrangian image point in the paraxial focal plane, by differentiating the OPD expression given above. The partial derivatives ∂OPD/∂x0 and ∂OPD/∂y0 represent respectively the components of the slope of the wave relative to the reference sphere at any particular point (x0, y0). Hence, because a ray is always perpendicular to the wave, the ray displacements in the focal plane can be found by
  and the product (hnu) is invariant for all the spaces between the lens surfaces, including the object and image spaces, for any lens system of any degree of complexity. This theorem has been named after the French scientist Joseph-Louis Lagrange, although it is sometimes called the Smith-Helmholtz theorem, after Robert Smith, an English scientist, and Hermann Helmholtz, a German scientist; the product (hnu) is often known as the optical invariant. As it is easy to determine the quantities h, n, and u for the original object, it is only necessary to calculate u′ by tracing a paraxial ray in order to find the image height h′ for any lens. If the lens is used in air, as most lenses are, the refractive indices are both unity, and the magnification becomes merely m = u/u′.

Your eyes are an important part of your health. Most people rely on their eyes to see and make sense of the world around them. But some eye diseases can lead to vision loss, so it is important to identify and treat eye diseases as early as possible. You should get your eyes checked as often as your health care provider recommends it, or if you have any new vision problems. And just as it is important to keep your body healthy, you also need to keep your eyes healthy.
There are two forms of dispersing element used to spread out the constituent colours of a beam of light into a “spectrum,” namely a prism and a grating. The prism, known to Newton, is the older; it separates the colours of the spectrum because the refractive index of the glass is lowest for red light and progressively increases through the yellow and green to the blue, where it is highest. Prism spectroscopes and spectrographs are made in a variety of forms and sizes, but in all cases the blue end of the spectrum is greatly spread out while the red end is relatively compressed.
To save face, keep the bedding clean from any pollen, dust, and dander that can accumulate on your sheets and pillowcases. It might be helpful to invest in a mattress cover to protect your sensitive eyes from dust mites looking for a cozy rest stop. Remember, pets can cause allergy symptoms to heighten, so consider keeping the animals outside the bedroom.
The cost of contact lenses depends on the type of lens being purchased and the vision problem that is being corrected. For nearsightedness, you'll be able to purchase a box of six lenses for roughly $25. Each lens needs to be replaced after a couple of weeks, which will require you to purchase 10 boxes of lenses each year, for a total of $250 per year. Contact lenses that treat other conditions like astigmatism and presbyopia are more expensive, and can cost $500-$700 a year.
Nope I came back to inform the dr the contacts were uncomfortable he failed to inform me it was a monthly pair he didn't give me a case when I left  so unfortunately I didn't get to try them on longer and had to dispose of them that night.. but I did go back the same day getting them and he said I don't prescribe blurry contacts and you just have to wear them longer ... he definitely is not open to what you have to say which is sad because I have to settle for something uncomfortable I didn't go back I don't need that type of negativity .. receptionists was super kind I wish he was the doctor ...
In Italy Optometry is unregulated profession. It is taught at seven universities: Padua, Turin, Milan, Salento,[34] Florence, Naples and Rome, as three years course (like a BSc) of "Scienze e tecnologie fisiche" as sector of the Physics Department. Additionally, courses are available at some private institutions (as at Vinci Institute near Firenze) that offer advanced professional education for already qualified opticians (most of the Italian optometrists are also qualified opticians, i.e. "ottico abilitato"). In the last thirty years several verdicts from High Court (Cassazione) proof that optometry is a freely practice and has truly education path.[35]
“I had to write to say thank you for all that was done for our son. Last February 2018 our son had his eyes tested at school. It came back and we were told they had some concerns. We went and took him to Vision Source of Farr West to have his eyes looked at; Ian Whipple is our doctor. I was surprised and almost started crying when I found out my sweet 6 year old boy could only read the top line of the chart. He has a bad astigmatism and without it being caught early could affect his vision into adulthood!! I was so heartbroken and felt so guilty I had no idea he couldn't sew and he never complained or had any signs of bad vision he never told me he couldn't see the clearly. So we immediately got him a pair of glasses to correct his astigmatism and vision problems. Over the past months this year his vision has drastically improved and his glasses became a part of who he was. It fits his personality and he was proud to wear them. . . Since our son has received his glasses his attention in class has improved he has been listening more to teachers and to me at home and he has excelled in school. His interest in reading is incredible he had no interest and now has a huge desire to read because now he can actually see what he is reading. . . Last year in Kindergarten I found out he was playing alone at recess because from far away he said he couldn't tell what kids were his friends. He had little friends he couldn't remember who they are and wouldn't identify them by their faces but by the color their jacket or shirt was. . . He now has so many friends I can't keep up on play dates. I never knew a pair of glasses could make him grow in such leaps and bounds. . . Thanks to the school's vision screening and Dr. Whipple our son now with his glasses has 20 /20 vision. I did not expect his eyes to do so well and now he can see the world more clearly than me! I hope this story inspires other parents to have their kids tested for their vision I thought our son could possibly have some social problems, little did I know his vision was affecting his life and behavior and possibly his future. Thanks to Vision Source of Farr West and their advanced testing our son has a brighter future and the possibilities are endless and crystal clear.”
The principal and focal points may be defined as follows: Figure 5 shows a lens system of any construction, with a bundle of rays entering from the left in a direction parallel to the lens axis. After refraction by the lens each ray will cross the axis at some point, and the entering and emerging portions of each ray are then extended until they intersect at a point such as Q. The locus of all the points Q is a surface of revolution about the lens axis known as the equivalent refracting locus of the lens. The point where this locus crosses the axis is called the principal point, P2, and the central portion of the locus in the neighbourhood of the axis, which is virtually a plane perpendicular to the axis, is called the principal plane. The point where the emerging paraxial ray crosses the axis is called the focal point F2, the distance from P2 to F2 being the (posterior) focal length f′. A similar situation exists for a parallel beam of light entering from the right, giving the anterior principal point P1, the anterior focal point F1, and the front focal length f. For a lens in air it can be shown that the two focal lengths are equal in magnitude but opposite in direction—i.e., if F2 is to the right of P2, then F1 must lie to the left of P1, as in the case of an ordinary positive lens (one that gives a real image). In a negative lens (one that gives a virtual image), F2 lies to the left of P2, and the posterior focal length f′ is negative.

Since the formation of the European Union, "there exists a strong movement, headed by the Association of European Schools and Colleges of Optometry (AESCO), to unify the profession by creating a European-wide examination for optometry" and presumably also standardized practice and education guidelines within EU countries.[30] The first examinations of the new European Diploma in Optometry were held in 1998 and this was a landmark event for optometry in continental Europe.[31]
DOPL requires a processing fee for initial license applications.  This fee varies by profession.  The Utah Legislature has authorized initial license fee waivers for qualifying military service members.  Full-time active duty service members should submit the fee waiver request form with their initial license application.  Download the fee waiver request form here.

I came to Standard Optical specifically for a laser surgery consult. My initial consult was with a male optometrist, whose name I can't recall. It was pretty basic and he said it seemed I'd be a good candidate for PRK. I had to do a pre-op appointment here as well, with deep dilation to get good measurements. Everyone was clear that it was possible I would arrive at the surgical center in Holladay and be told that I wasn't actually a good candidate, given my extreme near-sightedness. They told me about the possibility of an ICL surgery, but not much beyond it being more expensive and a lens is inserted. I took away one star because I feel the doctors should have been more careful in telling me I was a good PRK candidate. When I went to down to Holladay on the day of my scheduled PRK procedure, I was told by the surgeon (Dr. Williams) that I was too near-sighted (more than -10) and I would not be happy with the results. He said the doctor at the Ogden location had measured me at just less than -10, which is the cutoff, and that's fine given the different technology they have at the Holladay location. However, if the Ogden doctor knew I was right at the cusp, I would have like to have been told that and used it to make up my mind about scheduling the PRK procedure. I only have one pair of eyes, I probably wouldn't risk it if I was at the extreme edge of permissibly. Also, when they told me about the ICL procedure, all they said was that it was more expensive. Honestly, it felt more like an upsell than a "this procedure could be better for you" discussion. In actuality, once Dr. Williams explained the procedure and pricing to me, the ICL is LESS profitable for Standard Optical (you pay more than LASIK/PRK because of the surgical center fees, the portion to SO is less than the laser procedures).


The cost of contact lenses depends on the type of lens being purchased and the vision problem that is being corrected. For nearsightedness, you'll be able to purchase a box of six lenses for roughly $25. Each lens needs to be replaced after a couple of weeks, which will require you to purchase 10 boxes of lenses each year, for a total of $250 per year. Contact lenses that treat other conditions like astigmatism and presbyopia are more expensive, and can cost $500-$700 a year.
After earn­ing their DO, optometrists must com­plete a min­i­mum of three more years of school. Once ful­ly licensed, optometrists are able to prac­tice optom­e­try, which includes per­form­ing eye exams and vision tests, prescribing/fitting con­tact lens­es, detect­ing eye abnor­mal­i­ties and pre­scrib­ing med­ica­tions for cer­tain eye con­di­tions and dis­eases.

March 8th is International Women's Day, a day when women are honored and their accomplishments celebrated worldwide. From medicine to law, entrepreneurship to corporate leadership, education to the military, women are achieving great strides in areas of business like never before. In addition to professional achievements, International Women's Day is...

As noted earlier, a thin rod or fibre of glass or other transparent material transmits light by repeated internal reflections, even when the rod is somewhat curved. An ordered bundle of rods or fibres is thus capable of taking an image projected upon one end of the bundle and reproducing it at the other end. A fibre-optics bundle can be fused together into a rigid channel, or it may be left flexible, only the ends being rigidly fastened together. Because a fibre bundle is exceedingly delicate, it must be handled with care; breaking a fibre would cause a black dot to appear in the reproduced image.


To interpret these aberrations, the simplest procedure is to find the components x′, y′ of the displacement of a ray from the Lagrangian image point in the paraxial focal plane, by differentiating the OPD expression given above. The partial derivatives ∂OPD/∂x0 and ∂OPD/∂y0 represent respectively the components of the slope of the wave relative to the reference sphere at any particular point (x0, y0). Hence, because a ray is always perpendicular to the wave, the ray displacements in the focal plane can be found by
Hellenic Ministry of Education founded the first department of Optometry at Technological Educational Institute of Patras in 2007. After protests from the department of Optics at Technological Educational Institute of Athens (the only department of Optics in Greece, until 2006), the Government changed the names of the departments to "Optics and Optometry" and included lessons in both optics and optometry. Optometrists-Opticians have to complete a 4-year undergraduate honours degree. Then the graduates can be admitted to postgraduate courses in Optometry at universities around the world.
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