Which central thickness leads to better centration in GP lenses?

• A. Thin CT
• B. Thick CT
• C. Either thickness equally
• D. Centration is independent of CT

Answer: (A)

Centration of a GP lens is influenced by the lens’ weight, which is tied to central thickness. A thinner central thickness reduces the lens mass and the forces the eyelids and tear film apply as you blink. With less weight and torque to contend with, the lens sits more congruently over the corneal apex and tracks with the lid dynamics, leading to more stable, centered positioning. In contrast, a thicker, heavier center can be more susceptible to lid pressure and tear‑film forces that push the lens off-center or tilt it, especially during blinking. So, a thinner central thickness tends to give better centration.