Which statement best describes toric lens markings?

Which statement best describes toric lens markings?

• A. Markings denote the diameter
• B. Markings denote edge profile
• C. Markings denote the base and axis orientation
• D. Markings denote center thickness

Answer: (C)

Toric lenses rely on different powers in different meridians, so placing the lens so its cylinder axis lines up with the eye’s astigmatic axis is essential for clear vision. The markings on these lenses provide a reference for that orientation, showing where the axis of the cylindrical power sits and, in some designs, how the base curve is oriented around the eye to help the lens seat correctly. This orientation information is what keeps the correction stable and accurate as the lens sits on the eye. Markings don’t indicate diameter, edge profile, or center thickness—the lens’s physical size or shape is not shown by these marks. Those characteristics are determined by other specifications and aren’t used to guide placement.

Toric lenses rely on different powers in different meridians, so placing the lens so its cylinder axis lines up with the eye’s astigmatic axis is essential for clear vision. The markings on these lenses provide a reference for that orientation, showing where the axis of the cylindrical power sits and, in some designs, how the base curve is oriented around the eye to help the lens seat correctly. This orientation information is what keeps the correction stable and accurate as the lens sits on the eye.

Markings don’t indicate diameter, edge profile, or center thickness—the lens’s physical size or shape is not shown by these marks. Those characteristics are determined by other specifications and aren’t used to guide placement.