Which technique known to limit soft toric lens rotation sits on the lower eyelid?

Which technique known to limit soft toric lens rotation sits on the lower eyelid?

• A. Truncation
• B. Rotation restriction
• C. Eyelid tack
• D. Lower-lid seating

Answer: (A)

Rotation of a soft toric lens can be tamed by designing the lens edge to engage the lower lid as a stabilizing feature. Truncation achieves this by creating a distinct inferior edge on the lens. When the lens sits on the eye, that truncated edge rests against the lower lid margin, providing a defined contact point that helps keep the toric axis oriented consistently. The lid contact acts like a stop that resists rotation, so the lens maintains its prescribed orientation more reliably. This specific edge design is what sets truncation apart from other methods, which rely on lid manipulation or different stabilization concepts rather than a bottom-edge interaction with the lower lid.

Rotation of a soft toric lens can be tamed by designing the lens edge to engage the lower lid as a stabilizing feature. Truncation achieves this by creating a distinct inferior edge on the lens. When the lens sits on the eye, that truncated edge rests against the lower lid margin, providing a defined contact point that helps keep the toric axis oriented consistently. The lid contact acts like a stop that resists rotation, so the lens maintains its prescribed orientation more reliably. This specific edge design is what sets truncation apart from other methods, which rely on lid manipulation or different stabilization concepts rather than a bottom-edge interaction with the lower lid.