what causes crazing optics
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Crazing Crazing is the phenomenon that produces a network of fine cracks on the surface of a material, for example in a glaze layer. Crazing frequently precedes fracture in some glassy thermoplastic polymers.razing occurs in some thermoplastics such as acrylonitrile butadiene styrene (ABS plastic) when stressed. It is a typical response in rubber toughening, where crazes are initiated at the surfaces of the rubber particles added to toughen the material.
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Floaters and Flashing Lights If you see jagged lines of light that last 10 to 20 minutes and happen in one or both eyes, this is probably a migraine caused by the spasm of blood vessels in the brain. If you don't develop a headache after, the light flashes are called ophthalmic migraine, or migraine without headache.
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Astronomical seeing The vertical scale of the wavefronts plotted is highly exaggerated. Astronomical seeing refers to the blurring and twinkling of astronomical objects such as stars caused by turbulent mixing in the Earth's atmosphere varying the optical refractive index.
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What is Corneal Neovascularization? Normally, the cornea is avascular, or lacking blood vessels, because it needs to be transparent to allow the passage of light for proper focus and sight. This lack of blood vessels means that the cornea must absorb oxygen from the air, and therefore any process that inhibits this absorption may cause corneal neovascularization. Most commonly, this pathology is caused by contact lens wear, with a greater incidence in prolonged contact lens wearers, considered anything over approximately 10 hours per day.
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Crazing Crazing occurs in some thermoplastics such as acrylonitrile butadiene styrene (ABS plastic) when stressed. It is a typical response in rubber toughening, where crazes are initiated at the surfaces of the rubber particles added to toughen the material.
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Flickering lights in vision, Headache and Sudden flash of lights Migraines are a common type of headache that can cause severe pain, aura or flashes in vision, and tingling. Tension headaches, caused by muscle tension, are marked by pain, pressure and tightness around the head. Ocular migraine usually refers to a type of migraine that can cause temporary blindness in one eye.
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- Keratoconus can cause substantial distortion of vision, with multiple images, streaking and sensitivity to light all often reported by the person. It is typically diagnosed in the person's adolescent years.everal other corneal ectatic disorders, also cause thinning of the cornea: 1  Keratoglobus is a very rare condition that causes corneal thinning primarily at the margins, resulting in a spherical, slightly enlarged eye. 2  It may be genetically related to keratoconus.
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Supply and Demand: The Market Mechanism This price is called an equilibrium price, since it balances the two forces of supply and demand. An equilibrium price is the price at which the quantity demanded is equal to the quantity supplied. The quantity supplied and demanded is also referred to as the equilibrium quantity.
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Squiggly Lines in the Eyes Vitreous syneresis. The most common cause of floaters is shrinkage of the vitreous humour. This gel-like substance consists of 99% water and 1% solid elements. The solid portion consists of a network of collagen and hyaluronic acid, with the latter retaining water molecules.
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- Crazing is the development of a network of fine ran-. dom cracks or fissures on the surface of concrete or. mortar caused by shrinkage of the surface layer. These. cracks are rarely more than 1/. 8 inch [3 mm] deep and. are more noticeable on steel-troweled surfaces. The.
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REMOVING STAINS AND CRAZING LINES DISCOLORATION FROM PORCELAIN, CHINA AND POTTERY Crazing can also happen during the vessel’s life time during rapid temperature changes (day/night, hot water / cold water, etc.). Often, for aesthetics reasons, the crazing effect is introduced by design and on purpose on Japanese, Chinese or Raku dishes or vessels – see examples above.
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Flash blindness While it is caused by bright light as is flash blindness, the welder's arc lasts for much longer than a flash, and emits ultraviolet rays that can damage the cornea. Flash blindness, in contrast, is caused by a single very brief exposure which oversaturates the retina, and is not usually accompanied by reports of pain.
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Scintillating scotoma Scintillating scotomas are most commonly caused by cortical spreading depression, a pattern of changes in the behavior of nerves in the brain during a migraine. Migraines, in turn, may be caused by genetic influences and hormones.
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How Vision Works When light rays reach an angulated surface of a different material, it causes the light rays to bend. This is called refraction. The eye has multiple angulated surfaces that cause light to bend. When everything is working correctly, light makes it through these four interfaces and arrives at the retina in perfect focus.
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- In other words, if the louvers or other projections cause a pattern of triangular shading on the glass, if the glass is annealed only, it may break. If they want to blame you for the crack, get pictures and ask them to show you the point of impact.
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What Causes Black Floaters in Eyes? Clumping in the vitreous humor is the most common cause of floaters, and it generally occurs with aging. Inflammation in the back of the eye, posterior uveitis, can be caused by an infection or an inflammatory disease, and it results in floaters. Bleeding or vitreous hemorrhaging is more serious, and it can be the result of an injury; one of the symptoms is the appearance of floaters.
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Overview Causes. The exact cause of optic neuritis is unknown. However, optic neuritis is believed to develop when the immune system mistakenly targets the substance covering your optic nerve (myelin), resulting in inflammation and damage to the myelin.he exact cause of optic neuritis is unknown. However, optic neuritis is believed to develop when the immune system mistakenly targets the substance covering your optic nerve (myelin), resulting in inflammation and damage to the myelin.
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- The double vision is caused by the abnormal surface of the eye distorting incoming light. 1  Keratoconus is the most common cause of double vision in an individual eye that is not corrected with glasses.  Infections of the cornea, such as herpes zoster (shingles) or herpes simplex can distort the cornea.
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- S Afr Optom 2011 70(4) 168-174 VR Moodley et al - Induced prismatic effects due to poorly fitting spectacle frames The South African Optometrist ISSN 0378-9411 169 the frame or if the prescribed spectacles tend to be somewhat heavy1-3. Spectacles are very important,
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Refractive Errors And Refraction: How The Eye Sees 1 If the eye is too short, light is not focused by the time it reaches the retina. 2  This causes farsightedness or hyperopia. 3  Curvature of the cornea. 4  If the cornea is not perfectly spherical, then the image is refracted or focused irregularly to create a condition called astigmatism.
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- Crazing on lenses. I have had conflicting answers to my question on why we see now and again a patient with lenses that have horrible crazing marks on the lenses, like what you would see on very old pottery.ince then many manufacturers have made really thin lenses that flex in the edger or in the frames with large A to B ratios. The powerpoint on Tharcles is pretty much what any edger manufacturer will recommend: Reduce chuck pressure Use proper cushioning pads Use proper base chucks etc.
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Optic neuritis Inflammation of the optic nerve causes loss of vision, usually because of the swelling and destruction of the myelin sheath covering the optic nerve. The most common cause is multiple sclerosis or ischemic optic neuropathy (Blood Clot). Blood Clot that supplies the optic nerve. Up to 50% of patients with MS will develop an episode of optic neuritis, and 20-30% of the time optic neuritis is the presenting sign of MS.
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Ocular Migraines Causes of Ocular Migraines. Some scientists think that ocular (visual) migraines are caused by or triggered by inflammatory substances released in the tissues surrounding the circulatory and nerve system of the head and brain. Ocular migraines may be due to stress and fatigue - the same probable causes of migraine headaches.
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Optic neuritis Inflammation of the optic nerve causes loss of vision, usually because of the swelling and destruction of the myelin sheath covering the optic nerve. The most common cause is multiple sclerosis or ischemic optic neuropathy (Blood Clot). Blood Clot that supplies the optic nerve.
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- S Afr Optom 2011 70(4) 168-174 VR Moodley et al - Induced prismatic effects due to poorly fitting spectacle frames. The South African Optometrist ISSN 0378-9411. 173. Figure 3: showing the ranges of the induced BI and BO horizon -.
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Floaters and Flashing Lights When the vitreous separates from the retina, you may see flashing lights once in a while, for a few weeks. If you see jagged lines of light that last 10 to 20 minutes and happen in one or both eyes, this is probably a migraine caused by the spasm of blood vessels in the brain.