The centration of a GP lens improves as the center of gravity becomes more which direction?

• A. Anterior
• B. Posterior
• C. Superior
• D. Inferior

Answer: (B)

Gravity acts on the lens according to where its weight is centered. When the center of gravity sits more posteriorly, the downward pull helps the lens seat firmly against the corneal surface and resist tilting or edge lifting. This natural settling promotes a more even fit over the cornea and thus better centration. If the center of gravity were more anterior, gravity would tend to tilt the lens forward and encourage decentration or edge lift. Lateral (superior/inferior) shifts can affect positioning, but the posteriorly weighted position best supports a stable, centered alignment on the cornea.