Silicone hydrogel lenses with water-rich surfaces

A hydrated silicone hydrogel contact lens, comprising:

• an anterior surface and an opposite posterior surface;
• a layered structural configuration from the anterior surface to the posterior surface, wherein the layered structural configuration includes an anterior outer hydrogel layer having a first water content, an inner layer having a second water content, and a posterior outer hydrogel layer having a third water content;
• and
• a water content gradient in the structural configuration from the inner layer to the anterior or posterior outer hydrogel layer in which the first and third water contents are higher than the second water content,
• wherein the inner layer is the bulk material of the hydrated silicone hydrogel contact lens and is composed of a silicone hydrogel material which is a copolymerization product of a silicone hydrogel lens formulation comprising (i) at least one hydrophilic vinylic monomer and (ii) at least one polysiloxane-containing vinylic monomer and/or at least one polysiloxane-containing vinylic macromer,
• wherein the anterior and posterior outer hydrogel layer independent of each other are composed of a crosslinked polymeric material that is not water-soluble and contains at least 10% by weight of water within its polymer matrix when fully hydrated and that comprises poly (ethylene glycol) chains which are designated as PEG chains,
• wherein the hydrated silicone hydrogel contact lens has:
• an oxygen transmissibility of at least about 40 barrers/mm;
• an elastic modulus (or Young's Modulus) of from about 0.3 MPa to about 1.8 MPa;
• and a critical coefficient of friction, designated as CCOF, of 0.046 or less.