Lubrication is important for contact lens comfort. Sometimes lenses become dry and uncomfortable. You can place rewetting drops in your eye while you're wearing lenses to hydrate your lenses and soothe your eyes.

Renu Contact Lens Moisture Drops
Renu Contact Lens Moisture Drops effectively lubricate and rewet soft contact lenses for more comfortable lens wear. 
Sensitive Eyes Rewetting Drops
Sensitive Eyes Rewetting Drops lubricate, rewet and help prevent deposit build-up on soft contact lenses for clearer, more comfortable lens wear.