In an illumination system, a lens can substantially collimate light that is emitted from a location on a light source. The emitted light can have a central light portion and a peripheral light portion. The lens can have a first surface that faces the light source and a second surface opposite the first surface. The first surface can include a first convex central portion and a first total internal reflection (TIR) portion. The second surface can include a second convex central portion and a second TIR portion. The first and second convex central portions can substantially collimate the central light portion via refraction at the first convex central portion and refraction at the second convex central portion. The first and second TIR portions can substantially collimate the peripheral light portion via total internal reflection at the first TIR portion and total internal reflection at the second TIR portion.