The ciliary muscle reproduces the effect of a lens and allows the eye to focus or blur vision. It became the emblem of the critical vision that Diller + Scofidio (+ Renfro) had in their research and experimentation, including most recently the High Line park design for New York City. Their interdisciplinary projects range from objects, installations, and performances to media and architecture. In recent years they have expanded? with a third partner joining their studio?to embrace projects on a larger urban scale. Diller + Scofidio (+Renfro) covers their development, documenting about twenty works, for the earliest to the most recent. It also includes essays investigating the studio?s contect, influences and strategies; some interviews with the architects; and a scheme showing the evolutiuon and growth of the studio from 1979 to today.