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...
38 KB (4,101 words) - 16:47, 14 August 2024
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 (6,758 words) - 19:20, 6 August 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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treat common vision disorders such as myopia, hyperopia, presbyopia and astigmatism. The first theoretical work on the potential of refractive surgery was...
34 KB (3,910 words) - 15:00, 3 July 2024
most common use is to treat refractive errors: myopia, hypermetropia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short...
52 KB (6,354 words) - 21:47, 1 August 2024
in substitution of the patient's crystalline, astigmatism is typically not corrected, as astigmatism is mainly attributable to a deformation of the cornea...
42 KB (5,013 words) - 20:08, 7 July 2024
all three main optical aberrations – spherical aberration, coma, and astigmatism. This is primarily used to enable wide fields of view, much larger than...
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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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may result in blurry vision, double vision, nearsightedness, irregular astigmatism, and light sensitivity leading to poor quality-of-life. Usually both...
66 KB (7,272 words) - 00:27, 26 July 2024
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) - 21:14, 7 August 2024
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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). 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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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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correct astigmatism. The disadvantages made this type fundamentally flawed for many wearers. The "astig"—named for its ability to manage astigmatism—or "bar-spring"...
12 KB (1,546 words) - 22:00, 29 May 2024
procedures. The Alpins Method uses vector mathematics to determine a goal for astigmatism correction and analyze factors involved if treatment fails to reach that...
14 KB (1,746 words) - 21:28, 17 July 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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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) - 17:38, 4 July 2024
common types of refractive error are near-sightedness, far-sightedness, astigmatism, and presbyopia. Near-sightedness results in far away objects being blurry...
36 KB (3,821 words) - 12:18, 24 July 2024
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...
17 KB (2,218 words) - 16:51, 8 August 2024
lens is a lens used to diagnose a type of refractive error known as astigmatism. The Stokes lens also known as variable power cross cylinder lens, in...
4 KB (356 words) - 00:01, 30 January 2023
optical systems, even those exhibiting optical aberrations, including astigmatism, have at least one stigmatic pair. Stigmatism is applicable only in the...
1,007 bytes (114 words) - 21:35, 20 January 2024
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) - 04:54, 8 August 2024
because it provides high-quality outcomes with less surgically induced astigmatism than ECCE, no suture-related problems, quick rehabilitation, and fewer...
43 KB (4,789 words) - 00:53, 9 May 2024
syndrome, an unusual congenital malformation associated with myopic astigmatism characterized by tilting of the intraocular tip of the optic nerve (the...
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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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whose axis are perpendicular to one another. This is used to search for astigmatism. Snellen chart Duochrome test: used to check the spherical component...
11 KB (1,353 words) - 09:36, 2 June 2024
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...
8 KB (825 words) - 03:58, 12 May 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