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How do toric eyeglass lenses correct astigmatism?
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Explanation of the refraction of light through different lenses.
Toric eyeglass lenses correct astigmatism by compensating for the nonuniform curvature of the eye's cornea.12
Because astigmatism causes the eye to focus light at different distances depending on its orientation, it results in blurred vision. A toric lens addresses this by featuring a surface with different refracting powers in different meridians. Specifically, these lenses are designed with a stronger curvature in one meridian than in the perpendicular meridian, similar to the shape of a teaspoon's bowl. By providing this varying degree of curvature, the lens effectively counteracts the underlying asymmetry of the cornea, allowing light to focus properly on the retina.231