Which is a potential side effect of improper lens fit?

The potential side effect of improper lens fit is reduced comfort. When contact lenses do not fit correctly on the eye, they can cause irritation and discomfort. This can manifest as feelings of dryness, pressure, or even pain. A proper fit ensures that the lens moves with the eye during blinking and provides an even distribution of tears under the lens, which is essential for comfort. An improper fit can result in excessive movement or a lens that is too tight, both of which compromise the wearer's comfort levels.

Other options do not reflect the consequences of a poor lens fit. Improved vision might be associated with well-fitted lenses but is not a side effect of improper fitting. Increased moisture retention typically implies that a lens is functioning well to maintain eye hydration, while enhanced eye health generally stems from safe and suitable lens use, which is unlikely if the fit is incorrect.