Why Do Contacts Need to Absorb Moisture?

Contact lenses do not always need to absorb moisture, as not all contacts have a water content. Those that do incorporate water start absorbing moisture from your eye as they dry out over time, but the reason these contacts have a water content is not for moisture at all.

Oxygen

• For optimal eye health, your eyes need to breathe oxygen. Because traditional soft contacts block oxygen flow to your eye, they incorporate water to oxygenate your eyes.

Traditional Soft Contacts

• The problem with traditional soft contacts is that when their water supply runs out, they absorb moisture from your eyes, resulting in dry eyes.

Silicone Hydrogel Contacts

• New silicone hydrogel contacts are made with an oxygen-permeable material, allowing your eyes to breathe oxygen so the contacts require a lower water content. However, over time these contacts still dehydrate.

Gas-Permeable Contacts

• Gas-permeable contacts have no water content. They allow oxygen to flow naturally to your eye, and unlike soft contacts, they don't absorb moisture from your eye.

Comfort

• Without moisture, your soft contacts will not sit comfortably on your eye and may feel sticky. However, gas-permeable contacts--though initially uncomfortable due to their rigidity--become easy to wear in spite of their lack of water, for these contacts do not inherently need moisture.