If a GP lens has an anterior center of gravity, which effect is most likely?

If a GP lens has an anterior center of gravity, which effect is most likely?

• A. Superior decentration
• B. Inferior drop
• C. No effect
• D. Enhanced edge lift

Answer: (B)

Gravity interacting with how the lens’ weight is distributed is what drives this result. If the GP lens has more mass toward the anterior (front) surface, the downward pull of gravity creates a torque that makes the heavier front portion pull toward the lower part of the eye. The lens then settles and tilts so that the inferior edge sits lower on the cornea, producing an inferior drop. If the mass were centered or heavier toward the posterior surface, the tilt would tend to be different, and with balanced weight you’d see less notable movement.

Gravity interacting with how the lens’ weight is distributed is what drives this result. If the GP lens has more mass toward the anterior (front) surface, the downward pull of gravity creates a torque that makes the heavier front portion pull toward the lower part of the eye. The lens then settles and tilts so that the inferior edge sits lower on the cornea, producing an inferior drop. If the mass were centered or heavier toward the posterior surface, the tilt would tend to be different, and with balanced weight you’d see less notable movement.