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;
• 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;
• a surface wettability characterized by having an average water contact angle of 80 degrees or less;
• and
• an oxygen transmissibility of at least 60 barrers/mm;
• a water content of from about 10% to about 75% by weight;
• an elastic modulus of from about 0.3 MPa to about 1.8 MPa.
• wherein the hydrated silicone hydrogel contact lens has no staining spot thereon after being dipped into a Sudan Black dye solution and then rinsed extensively in water,
• wherein the inner layer is the bulk material of the hydrated silicone hydrogel contact lens and is composed of a silicone hydrogel material obtained by polymerizing a silicone hydrogel lens formulation comprising a vinylic monomer having a carboxyl group, a primary amino group, and/or a secondary amino group,
• wherein each of the anterior and posterior outer hydrogel layers is composed of a crosslinked polymeric material that comprises polymer chains derived from a copolymer which is a polymerization product of a composition comprising (i) about 60% by weight or less of at least one reactive vinylic monomer and (ii) at least one phosphorylcholine-containing vinylic monomer.