A LED lamp has at least two LEDs to provide light of at least two different spectral outputs. An optic element has an entry surface disposed to receive the light from the LEDs. The entry surface includes refracting surfaces that refract the light tangentially. The refracting surfaces may extend radially relative to a center of the entry surface. The refracting surfaces may be continuously curved in cross-section where the refracting surfaces may include convex refracting surfaces and concave refracting surfaces.