Which condition occurs only on the eye?

• A. Warpage
• B. Flexure
• C. Tear exchange
• D. Decentration

Answer: (B)

Flexure refers to a bending or deformation that happens in the eye’s own tissues due to dynamic forces like blinking and the eye’s natural structure. It is an on-eye phenomenon—the eye itself undergoes this change, independent of external objects. The other options describe changes or phenomena that involve the lens or tear film rather than the eye’s tissue changing shape on its own: warpage is a corneal distortion induced by contact lens wear, tear exchange is the movement of tears in the tear film under a lens, and decentration is a misalignment between the lens and the pupil or visual axis. So, the only occurrence that happens inherently on the eye is flexure.