Toric Contact Lenses
What are Toric Contact Lenses?
Toric contacts are contact lenses that correct astigmatism. The name “toric lens” indicates that it’s shaped in a particular way—a torus. A torus is a geometric shape that looks like a ring. A toric lens is shaped like a slice of the side of this ring. This shape creates different focusing powers on the vertical and horizontal orientations. If you are prescribed toric contacts, there will be a cylinder (CYL) and an axis (AX) column on your contact lens prescription. The cylinder indicates the amount of lens power for astigmatism, while the axis represents the lens meridian that has no cylinder power to correct astigmatism.
What is Astigmatism?
Astigmatism is a condition where the cornea is a curved, irregular shape (similar to a football) instead of round. This means that light is not being evenly distributed through the cornea onto the retina, resulting in blurry vision. There are two types of astigmatism—regular and irregular. Regular astigmatism, the most common type of astigmatism, is when the cornea is curved more in one direction than in the other. Irregular astigmatism is when the cornea has an uneven curvature.
Wearing Toric Contact Lenses
Since toric contacts have a particular orientation that’s different from other contact lenses, they need to rest on your eyes a certain way. However, the lens is designed (with thicker/heavier zones) to self-correct and stay put so you don’t have to worry about putting the lens in your eye the wrong way. A well-fitted lens is the key to a quick adjustment period. Toric contact lenses have a middle axis that keeps your line of vision clear. If your lenses slip and shift out of position, blurry vision occurs. Use rewetting drops to move the lens back into place. While that may happen on occasion if your contacts are dry, a persistent problem means that a re-fitting is necessary.