A method for producing soft contact lenses, comprising the steps of: obtaining a preformed silicone hydrogel contact lens in a dry state; subjecting the preformed silicone hydrogel contact lens in the dry state to a surface treatment to obtain a silicone hydrogel contact lens with a base coating thereon, wherein the base coating comprises a prime plasma layer, a reactive polymer layer on top of the prime plasma layer, and reactive functional groups selected from the group consisting of carboxyl groups, primary amino groups, secondary amino groups, and combinations thereof, wherein the surface treatment comprises the sub-steps of (a) plasma-treating the surface of the preformed silicone hydrogel contact lens in the dry state with a plasma to obtain a silicone hydrogel contact lens with the prime plasma layer thereon, wherein the plasma is generated in a plasma gas composed of a mixture of an unsaturated C 2 -C 4 hydrocarbon and CO 2, wherein the prime plasma layer has a thickness of from 0.5 nm to 40 nm, and (b) contacting the silicone hydrogel contact lens with the prime plasma layer thereon with a first aqueous solution including a reactive hydrophilic polymer having multiple reactive functional groups selected from the group consisting of carboxyl groups, primary amino groups, secondary amino groups, and combinations thereof to form the base coating which include the reactive polymer layer of the reactive hydrophilic polymer on top of the prime plasma layer; and heating the silicone hydrogel contact lens with the base coating thereon obtained in step, in a second aqueous solution which comprises a water-soluble and thermally-crosslinkable hydrophilic polymeric material having azetidinium groups and optionally primary or secondary amino groups and/or carboxyl groups, at a temperature of from 60°C to 140°C for a time period sufficient long to crosslink the water-soluble thermally-crosslinkable hydrophilic polymeric material and the base coating so as to form a hydrogel coating on the silicone hydrogel contact lens, wherein the silicone hydrogel contact lens in fully hydrated state has a WBUT of at least 10 seconds and a friction rating of 3 or lower. obtaining a preformed silicone hydrogel contact lens in a dry state; subjecting the preformed silicone hydrogel contact lens in the dry state to a surface treatment to obtain a silicone hydrogel contact lens with a base coating thereon, wherein the base coating comprises a prime plasma layer, a reactive polymer layer on top of the prime plasma layer, and reactive functional groups selected from the group consisting of carboxyl groups, primary amino groups, secondary amino groups, and combinations thereof, wherein the surface treatment comprises the sub-steps of (a) plasma-treating the surface of the preformed silicone hydrogel contact lens in the dry state with a plasma to obtain a silicone hydrogel contact lens with the prime plasma layer thereon, wherein the plasma is generated in a plasma gas composed of a mixture of an unsaturated C 2 -C 4 hydrocarbon and CO 2, wherein the prime plasma layer has a thickness of from 0.5 nm to 40 nm, and (b) contacting the silicone hydrogel contact lens with the prime plasma layer thereon with a first aqueous solution including a reactive hydrophilic polymer having multiple reactive functional groups selected from the group consisting of carboxyl groups, primary amino groups, secondary amino groups, and combinations thereof to form the base coating which include the reactive polymer layer of the reactive hydrophilic polymer on top of the prime plasma layer; and (a) plasma-treating the surface of the preformed silicone hydrogel contact lens in the dry state with a plasma to obtain a silicone hydrogel contact lens with the prime plasma layer thereon, wherein the plasma is generated in a plasma gas composed of a mixture of an unsaturated C 2 -C 4 hydrocarbon and CO 2, wherein the prime plasma layer has a thickness of from 0.5 nm to 40 nm, and (b) contacting the silicone hydrogel contact lens with the prime plasma layer thereon with a first aqueous solution including a reactive hydrophilic polymer having multiple reactive functional groups selected from the group consisting of carboxyl groups, primary amino groups, secondary amino groups, and combinations thereof to form the base coating which include the reactive polymer layer of the reactive hydrophilic polymer on top of the prime plasma layer; and heating the silicone hydrogel contact lens with the base coating thereon obtained in step, in a second aqueous solution which comprises a water-soluble and thermally-crosslinkable hydrophilic polymeric material having azetidinium groups and optionally primary or secondary amino groups and/or carboxyl groups, at a temperature of from 60°C to 140°C for a time period sufficient long to crosslink the water-soluble thermally-crosslinkable hydrophilic polymeric material and the base coating so as to form a hydrogel coating on the silicone hydrogel contact lens, wherein the silicone hydrogel contact lens in fully hydrated state has a WBUT of at least 10 seconds and a friction rating of 3 or lower.