[1][3] Diagnosis is by an eye examination called autorefractor keratometry (objective, allows to see lens and cornea components of astigmatism) and subjective refraction.

[1] Refractive surgery aims to permanently change the shape of the eye and thereby cure astigmatism.

In a study conducted in 2011 on various Asian populations, variants in the PDGFRA gene on chromosome 4q12 were identified to be associated with corneal astigmatism.

[10] A follow-up study in 2013 on the European population, however, found no variant significantly associated with corneal astigmatism at the genome-wide level (single-nucleotide polymorphism rs7677751 at PDGFRA).

[11] Facing the inconsistency, a study by Shah and colleagues in 2018 included both populations with Asian and Northern European ancestry.

[12] Other GWAS studies also provided inconclusive results: Lopes and colleagues identified a susceptibility locus with lead single nucleotide polymorphism rs3771395 on chromosome 2p13.3 in the VAX2 gene (VAX2 plays an important role in the development of the dorsoventral axis of the eye);[13] Li and associates, however, found no consistent or strong genetic signals for refractive astigmatism while suggesting a possibility of widespread genetic co-susceptibility for spherical and astigmatic refractive errors.

[medical citation needed] Irregular astigmatism, which is often associated with prior ocular surgery or trauma, is also a common naturally occurring condition.

[20] With accommodation relaxed: Astigmatism, whether it is regular or irregular, is caused by some combination of external (corneal surface) and internal (posterior corneal surface, human lens, fluids, retina, and eye-brain interface) optical properties.

Importantly, the axes and magnitudes of external and internal astigmatism do not necessarily coincide, but it is the combination of the two that by definition determines the overall optics of the eye.

[21][22] A number of tests are used during eye examinations to determine the presence of astigmatism and to quantify its amount and axis.

A keratometer may be used to measure the curvature of the steepest and flattest meridians in the cornea's front surface.

[24] An autorefractor or retinoscopy may provide an objective estimate of the eye's refractive error and the use of Jackson cross cylinders in a phoropter or trial frame may be used to subjectively refine those measurements.

[25][26][27] An alternative technique with the phoropter requires the use of a "clock dial" or "sunburst" chart to determine the astigmatic axis and power.

[1] Glasses are the simplest and safest, although contact lenses can provide a wider field of vision.

Various considerations involving eye health, refractive status, and lifestyle determine whether one option may be better than another.

In those with keratoconus, certain contact lenses often enable patients to achieve better visual acuity than eyeglasses.

Toric intraocular lenses probably provide a better outcome with respect to astigmatism in these cases than limbal relaxing incisions.

[32] In 2019, the World Health Organization reported that 123.7 million people worldwide were affected by uncorrected refracting errors, including astigmatism.

[36] Studies have shown that infants in their first few months have a high prevalence of astigmatism due to a steep cornea.

[33] People with astigmatism have more difficulty with night driving and can have a decreased productivity due to errors.

[41] Independent from Young, George Biddell Airy discovered the phenomenon of astigmatism on his own eye.