Astigmatism

Astigmatism
Astigmatism
	Blur from astigmatic lens at different distances
Specialty	Ophthalmology, optometry
Symptoms	Distorted or blurred vision at all distances, eyestrain, headaches
Complications	Amblyopia
Causes	Unclear
Diagnostic method	Eye exam
Treatment	Glasses, contact lenses, surgery
Frequency	30% to 60% of adults (Europe, Asia)

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]

^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Cite error: The named reference NIH2010 was invoked but never defined (see the help page).
^ ^a ^b Harvey, 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.
^ ^a ^b ^c ^d Read, 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.
^ ^a ^b ^c Mozayan, 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.

[NIH2010-1] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k Cite error: The named reference NIH2010 was invoked but never defined (see the help page).

[Har2009-2] Harvey, 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.

[Read2007-3] Read, 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.

[Moz2014-4] Mozayan, 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.

[5] "The Ultimate Guide to Astigmatism". Feel Good Contacts.

[6] "Thomas Young | British physician and physicist". Encyclopædia Britannica. Archived from the original on 29 August 2017. Retrieved 28 August 2017.

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