what are toric contact lenses

Toric contact lenses are a type of contact lens designed to correct astigmatism, which is caused by a different curvature of the cornea or lens in the eye. Unlike standard contact lenses, which have a spherical surface, toric lenses have a unique shape that looks like a slice of the side of a donut. This shape creates different focusing powers on the vertical and horizontal orientations, which corrects the refractive error caused by astigmatism. Toric lenses have a middle axis that keeps the line of vision clear, and they need to stay on the eye in the correct way to work effectively. Manufacturers design toric contact lenses with features to help the lenses stay put, including thin-thick zones, lens truncation, and ballasting. Toric contact lenses come in both soft and rigid gas permeable (RGP) lenses, and they can be prescribed for daily, biweekly, and monthly wear schedules. A well-fitted lens is the key to a quick adjustment period, and fitting is especially critical for toric contacts.