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 (4,093 words) - 06:06, 23 April 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
surgery for the correction of myopia, hyperopia, and an actual cure for astigmatism, since it is in the cornea. LASIK surgery is performed by an ophthalmologist...
63 KB (7,379 words) - 19:17, 15 May 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...
7 KB (804 words) - 19:47, 16 June 2023
in substitution of the patient's crystalline, astigmatism is typically not corrected, as astigmatism is mainly attributable to a deformation of the cornea...
41 KB (4,932 words) - 20:49, 4 April 2024
presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism. Benjamin Franklin is generally credited with the invention of bifocals...
8 KB (892 words) - 02:45, 9 May 2024
most common use is to treat refractive errors: myopia, hypermetropia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short...
50 KB (6,216 words) - 02:44, 9 May 2024
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
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) - 04:14, 13 November 2023
implantation. Other common types of refractive errors are near-sightedness, astigmatism, and presbyopia. In young patients, mild hypermetropia may not produce...
23 KB (2,169 words) - 23:59, 21 April 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 (3,909 words) - 15:24, 4 May 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"...
12 KB (1,546 words) - 10:01, 3 May 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...
57 KB (8,674 words) - 23:22, 21 December 2023
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
). For example, the KISA% index (keratometry, I-S, skew percentage, astigmatism) is used to arrive at a diagnosis of keratoconus, to screen the suspect...
11 KB (1,326 words) - 23:01, 23 December 2023
Oscilloscope (section Astigmatism)
An oscilloscope (informally scope or O-scope) is a type of electronic test instrument that graphically displays varying voltages of one or more signals...
64 KB (8,498 words) - 01:27, 12 April 2024
may result in blurry vision, double vision, nearsightedness, irregular astigmatism, and light sensitivity leading to poor quality-of-life. Usually both...
65 KB (7,173 words) - 19:03, 15 May 2024
following Airy's development of methods to measure and correct ocular astigmatism. It has only recently[when?] become possible to measure the aberrations...
17 KB (2,071 words) - 09:11, 12 February 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 (2,217 words) - 03:02, 4 September 2023
thin slit through it used by optometrists in detecting the level of an astigmatism. The disk is rotated so that the slit is oriented at different angles...
928 bytes (113 words) - 11:43, 23 April 2024
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 (3,469 words) - 11:19, 22 March 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
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...
22 KB (968 words) - 10:58, 11 May 2024
Examples of refractive error are myopia, hyperopia, presbyopia and astigmatism. The errors are specified in diopters, in a similar format to an eyeglass...
17 KB (2,079 words) - 09:10, 16 March 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...
15 KB (1,785 words) - 00:02, 20 April 2024
point that is considerably closer than infinity. A condition known as astigmatism results when the cornea is not spherical but instead is more curved in...
106 KB (12,848 words) - 20:35, 5 April 2024
primarily in eyeglasses, contact lenses and intraocular lenses to correct astigmatism. A torus is the surface of revolution resulting when a circle with radius...
5 KB (553 words) - 13:25, 21 December 2022
Javal's rule is a mathematical formula used to estimate astigmatism based on keratometry readings. The estimate is useful for high cylinder measures,...
643 bytes (72 words) - 16:10, 7 November 2020
astigmatic lens. An example is eyeglass lenses that are used to correct astigmatism in someone's eye. Lenses are classified by the curvature of the two optical...
56 KB (6,824 words) - 22:41, 12 May 2024
of refractive error along with nearsightedness, farsightedness, and astigmatism. Diagnosis is by an eye examination. Presbyopia can be corrected using...
22 KB (2,244 words) - 23:19, 14 May 2024