Astigmatism is a type of refractive error due to rotational asymmetry in the eye's refractive power. This results in distorted or blurred vision at any...
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system with astigmatism is one where rays that propagate in two perpendicular planes have different foci. If an optical system with astigmatism is used to...
17 KB (1,934 words) - 12:23, 13 September 2023
type of refractive surgery for the correction of myopia, hyperopia, and astigmatism. LASIK surgery is performed by an ophthalmologist who uses a femtosecond...
59 KB (6,439 words) - 03:43, 15 September 2024
Jackson cross cylinder (section Detecting astigmatism)
particularly in determination of corrective lens power in patients with astigmatism. It is also used for testing near point of the eye. Jackson cross cylinder...
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in substitution of the patient's crystalline, astigmatism is typically not corrected, as astigmatism is mainly attributable to a deformation of the cornea...
43 KB (5,067 words) - 22:24, 25 September 2024
all three main optical aberrations – spherical aberration, coma, and astigmatism. This is primarily used to enable wide fields of view, much larger than...
12 KB (1,370 words) - 16:59, 25 June 2024
most common use is to treat refractive errors: myopia, hypermetropia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short...
53 KB (6,362 words) - 01:42, 5 September 2024
treat common vision disorders such as myopia, hyperopia, presbyopia and astigmatism. The first theoretical work on the potential of refractive surgery was...
34 KB (3,901 words) - 00:41, 16 September 2024
correct astigmatism. The disadvantages made this type fundamentally flawed for many wearers. The "astig"—named for its ability to manage astigmatism—or "bar-spring"...
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presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism. Benjamin Franklin is generally credited with the invention of bifocals...
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Optical aberration (section Aberration of lateral object points (points beyond the axis) with narrow pencils — astigmatism)
common monochromatic aberrations are: Defocus Spherical aberration Coma Astigmatism Field curvature Image distortion Although defocus is technically the...
58 KB (8,720 words) - 01:47, 17 September 2024
implantation. Other common types of refractive errors are near-sightedness, astigmatism, and presbyopia. In young patients, mild hypermetropia may not produce...
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). For example, the KISA% index (keratometry, I-S, skew percentage, astigmatism) is used to arrive at a diagnosis of keratoconus, to screen the suspect...
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following Airy's development of methods to measure and correct ocular astigmatism. It has only recently[when?] become possible to measure the aberrations...
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procedures. The Alpins Method uses vector mathematics to determine a goal for astigmatism correction and analyze factors involved if treatment fails to reach that...
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the drooping eyelid can cause other conditions, such as amblyopia or astigmatism, so it is especially important to treat the disorder in children before...
30 KB (3,461 words) - 18:37, 5 September 2024
may result in blurry vision, double vision, nearsightedness, irregular astigmatism, and light sensitivity leading to poor quality-of-life. Usually both...
66 KB (7,271 words) - 18:13, 3 September 2024
Cook was declared legally blind in the second grade because of severe astigmatism, but wore contacts and thick "Coke bottle" glasses to correct her vision...
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Phacolytic glaucoma (section Astigmatism correction)
conducted to determine how much nearsightedness, farsightedness and/or astigmatism an individual may have. Additional specific measurements of the eye will...
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and have poor eyesight. In domestic animals, myopia, with or without astigmatism, occurs frequently. Evolved for low-light hunting, cats' eyes are proportionally...
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optical systems, even those exhibiting optical aberrations, including astigmatism, have at least one stigmatic pair. Stigmatism is applicable only in the...
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Examples of refractive error are myopia, hyperopia, presbyopia and astigmatism. The errors are specified in diopters, in a similar format to an eyeglass...
18 KB (2,190 words) - 18:03, 10 September 2024
the rod can be given as : Cylindrical lenses are prescribed to correct astigmatism. Cross cylinder, which is a combination of two cylindrical lenses with...
5 KB (508 words) - 22:59, 31 March 2024
common types of refractive error are near-sightedness, far-sightedness, astigmatism, and presbyopia. Near-sightedness results in far away objects being blurry...
37 KB (3,833 words) - 15:35, 10 September 2024
is an Australian ophthalmologist who developed the Alpins method of astigmatism analysis used in refractive, corneal, and cataract surgery, used in the...
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because it provides high-quality outcomes with less surgically induced astigmatism than ECCE, no suture-related problems, quick rehabilitation, and fewer...
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of refractive error along with nearsightedness, farsightedness, and astigmatism. Diagnosis is by an eye examination. Presbyopia can be corrected using...
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Hefilcon B 45 10 Optima Toric Alphafilcon A 66 32 SofLens Toric for Astigmatism Omafilcon A 58-60 28–36.7 Proclear 1-Day, Proclear EP, Proclear 1 day...
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A stigmator is a component of electron microscopes that reduces astigmatism of the beam by imposing a weak electric or magnetic quadrupole field on the...
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Refractive errors include near-sightedness, far-sightedness, presbyopia, and astigmatism. Cataracts are the most common cause of blindness. Other disorders that...
90 KB (10,397 words) - 07:13, 26 September 2024