Definition of astigmatism in English:



  • A defect in the eye or in a lens caused by a deviation from spherical curvature, which results in distorted images, as light rays are prevented from meeting at a common focus.

    • ‘In astigmatism, although the eye is perfectly healthy, the cornea is curved more like the surface of an egg, with a steep curve in one meridian and a flatter curve in others.’
    • ‘People with astigmatism usually need to wear glasses or contact lenses to correct their vision.’
    • ‘Contact lenses can balance the image from both eyes, and correct any irregularities or astigmatism of the eye.’
    • ‘In astigmatism, the refractive power of the eye is different in different meridians.’
    • ‘Corrective lenses such as contact lenses or glasses can usually correct vision in people with astigmatism.’
    • ‘Most refractive surgical procedures were developed to correct nearsightedness, farsightedness and astigmatism.’
    • ‘It is a surgical treatment for short-sightedness, some forms of long-sightedness and astigmatism and is carried out by ophthalmic surgeons.’
    • ‘In fact about 23% of the lenses sold in Australia are sold to correct astigmatism.’
    • ‘Toric contact lenses can correct astigmatism for most people.’
    • ‘The glasses do not correct astigmatism, but they are effective against nearsightedness and farsightedness.’
    • ‘For pure astigmatism, a lens is required that has no optical power in the normal meridian but has appropriate curvature in the others.’
    • ‘Amblyopia can also result from a major difference in the refraction between the two eyes, such as nearsightedness, farsightedness, or astigmatism.’
    • ‘Suitable for most people who need glasses, including those who are short-sighted, long-sighted or have astigmatism, laser eye surgery treatment is quick, easy and affordable.’
    • ‘Apart from testing the eye, they supply booklets detailing eye care with particular reference to refractive errors such as myopia, hypermetropia and astigmatism.’
    • ‘Side vision is distorted and oblique rays of light passing through a spherical lens produce astigmatism.’
    • ‘Whether myopia, hyperopia or astigmatism is present, surgical correction attempts to redirect light rays to accommodate the refractive error.’
    • ‘The degree of astigmatism should not exceed more than four diopters.’
    • ‘For lower amounts of astigmatism, often standard lens designs can be used.’
    • ‘The surfaces of the lens or cornea may not be smooth, causing an aberration that results in a streak of distortion called astigmatism.’
    • ‘They aren't as effective in correcting some vision problems, including high degrees of astigmatism, as are rigid lenses.’


Mid 19th century: from a- without + Greek stigma point + -ism.