An optical lens with different refractive powers in two principal meridians. Correcting regular ocular astigmatism requires both the power difference and its orientation.
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A toric lens is a type of lens designed to correct astigmatism, which is a common refractive error caused by an irregular shape of the cornea or lens of the eye. Unlike spherical lenses, which have a uniform curvature, toric lenses have different curvatures in different meridians (or axes) to compensate for the uneven shape of the eye. Toric lenses can be found in both glasses and contact lenses.