If a lens diameter is too small, which issue is most likely?

• A. Poor centration
• B. Excessive movement
• C. Minimal movement
• D. Increased wearer comfort

Answer: (B)

When a lens diameter is too small, the lens doesn’t cover enough of the corneal surface or engage the peripheral area well enough to be stabilized by the eyelids. That lack of stable support means the lens can slide or shift with each blink, leading to excessive movement on the eye. This is the most direct and likely consequence of an undersized diameter, because the lens isn’t held in place by the surrounding cornea and lid interaction. Minimal movement wouldn’t typically be expected in this scenario, and increased comfort isn’t likely since the instability and edge interplay from the small diameter tend to cause discomfort or vision fluctuations. While poor centration can occur as a result of movement, the primary and most probable issue with a lens that is too small is excessive movement.