Which property tends to increase with higher water content, aside from pore size?

Which property tends to increase with higher water content, aside from pore size?

• A. Oxygen transmissibility
• B. Adsorption of tear solutes
• C. Pore size
• D. Modulus

Answer: (B)

When a hydrogel contact lens takes up more water, the polymer network swells and becomes more hydrated, with more polar regions and wider free volume. This environment favors interactions with tear film components, so tear solutes—ions, proteins, and other polar molecules—are more readily taken up and held by the lens. In other words, the increased water content enhances the lens’s ability to adsorb tear solutes. Pore size indeed increases with hydration, which is already considered in the question. The lens’s stiffness (modulus) typically decreases as water content rises, making it softer, rather than increasing. Oxygen transmissibility can also rise with hydration, but the option describing adsorption of tear solutes best captures the direct effect of higher water content on interactions with the tear film.

When a hydrogel contact lens takes up more water, the polymer network swells and becomes more hydrated, with more polar regions and wider free volume. This environment favors interactions with tear film components, so tear solutes—ions, proteins, and other polar molecules—are more readily taken up and held by the lens. In other words, the increased water content enhances the lens’s ability to adsorb tear solutes.

Pore size indeed increases with hydration, which is already considered in the question. The lens’s stiffness (modulus) typically decreases as water content rises, making it softer, rather than increasing. Oxygen transmissibility can also rise with hydration, but the option describing adsorption of tear solutes best captures the direct effect of higher water content on interactions with the tear film.