Multilayered interlayers comprising stiff skin layers and a soft core layer(s) are disclosed. The multilayered interlayers comprise: a first polymer layer (skin layer) comprising plasticized poly(vinyl butyral) resin; a second polymer layer (core layer) comprising a blend of two or more plasticized poly(vinyl butyral) resins having different residual hydroxyl content wherein the plasticizer is a high refractive index plasticizer having a refractive index of at least about 1.460; and optionally, a third polymer layer (skin layer) comprising plasticized poly(vinyl butyral) resin.