"Astigmatic" redirects here. For the album, see Astigmatic (album).
For the more general class of optical aberrations, see Astigmatism (optical systems).
Medical condition
Astigmatism
Blur from astigmatic lens at different distances
Specialty
Ophthalmology, optometry
Symptoms
Distorted or blurred vision at all distances, eyestrain, headaches[1]
Complications
Amblyopia[2]
Causes
Unclear[3]
Diagnostic method
Eye exam[1]
Treatment
Glasses, contact lenses, surgery[1]
Frequency
30% to 60% of adults (Europe, Asia)[4]
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 distance.[1] Other symptoms can include eyestrain, headaches, and trouble driving at night.[1] Astigmatism often occurs at birth and can change or develop later in life.[5] If it occurs in early life and is left untreated, it may result in amblyopia.[2]
The cause of astigmatism is unclear; however, it is believed to be partly related to genetic factors.[3][4] The underlying mechanism involves an irregular curvature of the cornea and protective reaction changes in the lens of the eye, called lens astigmatism, that has the same mechanism as spasm of accommodation.[1][3] Diagnosis is by an eye examination called autorefractor keratometry (objective, allows to see lens and cornea components of astigmatism) and subjective refraction.
Three treatment options are available: glasses, contact lenses, and surgery.[1] Glasses are the simplest.[1] Contact lenses can provide a wider field of vision and fewer artifacts than even double aspheric lenses.[1] Refractive surgery aims to permanently change the shape of the eye and thereby cure astigmatism.[1]
In Europe and Asia, astigmatism affects between 30% and 60% of adults.[4] People of all ages can be affected by astigmatism.[1] Astigmatism was first reported by Thomas Young in 1801.[3][6]
^ abcdefghijkCite error: The named reference NIH2010 was invoked but never defined (see the help page).
^ abHarvey, EM (June 2009). "Development and treatment of astigmatism-related amblyopia". Optometry and Vision Science. 86 (6): 634–9. doi:10.1097/opx.0b013e3181a6165f. PMC 2706277. PMID 19430327.
^ abcdRead, SA; Collins, MJ; Carney, LG (January 2007). "A review of astigmatism and its possible genesis". Clinical & Experimental Optometry. 90 (1): 5–19. doi:10.1111/j.1444-0938.2007.00112.x. PMID 17177660. S2CID 8876207.
^ abcMozayan, E; Lee, JK (July 2014). "Update on astigmatism management". Current Opinion in Ophthalmology. 25 (4): 286–90. doi:10.1097/icu.0000000000000068. PMID 24837578. S2CID 40929023.
^"The Ultimate Guide to Astigmatism". Feel Good Contacts.
^"Thomas Young | British physician and physicist". Encyclopædia Britannica. Archived from the original on 29 August 2017. Retrieved 28 August 2017.
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...
in substitution of the patient's crystalline, astigmatism is typically not corrected, as astigmatism is mainly attributable to a deformation of the cornea...
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...
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...
most common use is to treat refractive errors: myopia, hypermetropia, astigmatism, and presbyopia. Glasses or "spectacles" are worn on the face a short...
presbyopia who also require a correction for myopia, hyperopia, and/or astigmatism. Benjamin Franklin is generally credited with the invention of bifocals...
optical systems, even those exhibiting optical aberrations, including astigmatism, have at least one stigmatic pair. Stigmatism is applicable only in the...
treat common vision disorders such as myopia, hyperopia, presbyopia and astigmatism. The first theoretical work on the potential of refractive surgery was...
implantation. Other common types of refractive errors are near-sightedness, astigmatism, and presbyopia. In young patients, mild hypermetropia may not produce...
common monochromatic aberrations are: Defocus Spherical aberration Coma Astigmatism Field curvature Image distortion Although defocus is technically the...
the rod can be given as : Cylindrical lenses are prescribed to correct astigmatism. Cross cylinder, which is a combination of two cylindrical lenses with...
procedures. The Alpins Method uses vector mathematics to determine a goal for astigmatism correction and analyze factors involved if treatment fails to reach that...
). For example, the KISA% index (keratometry, I-S, skew percentage, astigmatism) is used to arrive at a diagnosis of keratoconus, to screen the suspect...
conducted to determine how much nearsightedness, farsightedness and/or astigmatism an individual may have. Additional specific measurements of the eye will...
An oscilloscope (informally scope or O-scope) is a type of electronic test instrument that graphically displays varying voltages of one or more signals...
following Airy's development of methods to measure and correct ocular astigmatism. It has only recently[when?] become possible to measure the aberrations...
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...
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...
Examples of refractive error are myopia, hyperopia, presbyopia and astigmatism. The errors are specified in diopters, in a similar format to an eyeglass...
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...
may result in blurry vision, double vision, nearsightedness, irregular astigmatism, and light sensitivity leading to poor quality-of-life. Usually both...
of refractive error along with nearsightedness, farsightedness, and astigmatism. Diagnosis is by an eye examination. Presbyopia can be corrected using...
primarily in eyeglasses, contact lenses and intraocular lenses to correct astigmatism. A torus is the surface of revolution resulting when a circle with radius...
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...
incision size and reduces the recovery time and risk of surgery induced astigmatism. It is best suited to relatively soft cataracts, where the ultrasonic...
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