If there is an increase in the diopter (D) of base curve, the contact lens will be flatter/steeper.

If there is an increase in the diopter (D) of base curve, the contact lens will be flatter/steeper.

• A. Flatter
• B. Steeper
• C. Unchanged
• D. Not predictable

Answer: (B)

Base curve describes how curved the back surface of a contact lens is. The diopter value of base curve is tied to curvature: higher diopters mean a shorter radius of curvature, which makes the surface steeper. So when the base-curve diopter increases, the lens becomes steeper, leading to a tighter, more snug fit against the cornea. If the diopter were lower, the radius would be larger and the lens would fit flatter. This is why increasing the base-curve diopter results in a steeper fit.

Base curve describes how curved the back surface of a contact lens is. The diopter value of base curve is tied to curvature: higher diopters mean a shorter radius of curvature, which makes the surface steeper. So when the base-curve diopter increases, the lens becomes steeper, leading to a tighter, more snug fit against the cornea. If the diopter were lower, the radius would be larger and the lens would fit flatter. This is why increasing the base-curve diopter results in a steeper fit.