Silicone hydrogel lenses with water-rich surfaces

A hydrated silicone hydrogel contact lens, comprising:

• an anterior surface and an opposite posterior surface;
• and
• a layered structural configuration from the anterior surface to the posterior surface,
• wherein the layered structural configuration includes an anterior outer hydrogel layer, an inner layer of a silicone hydrogel material, and a posterior outer hydrogel layer,
• wherein the inner layer is a preformed silicone hydrogel contact lens made from a silicone hydrogel lens formulation comprising a hydrophilic vinylic monomer and a polysiloxane-containing vinylic monomer or macromer,
• wherein the inner layer of the silicone hydrogel material has an oxygen permeability of at least about 50 Barrers, a first water content WCSiHy of from about 10% to about 65% by weight, and an elastic modulus of from about 0.3 MPa to about 1.8 MPa,
• wherein the anterior and posterior outer hydrogel layers are substantially uniform in thickness and merge at the peripheral edge of the contact lens to completely enclose the inner layer of the silicone hydrogel material,
• wherein the anterior and posterior outer hydrogel layers independent of each other have a second water content higher than WCSiHy, as characterized either (a) by having a water-swelling ratio WSR of at least about 150% if WCSiHy≦45% or (b) by having a water-swelling ratio of at least about
• 130
• ·
• WC
• SiHy
• 1
• -
• WC
• SiHy
• 
• %
• if WCSiHy>45%,
• wherein the thickness of each of the anterior and posterior outer hydrogel layers is from about 0.1 μm to about 20 μm, as measured with atomic force microscopy across a cross section from the posterior surface to the anterior surface of the silicone hydrogel contact lens in fully hydrated state.