NFIRAOS (Narrow Field InfraRed Adaptive Optics System, pronounced nefarious) is the first light adaptive optics
system for the Thirty Meter Telescope (TMT). It is a near-IR, diffraction limited, multi-conjugate adaptive optics
(MCAO) system that uses two deformable mirrors to correct aberrations due to atmospheric turbulence. The f/15 beam
delivered by the telescope, with a two arc-minute field of view, is relayed to one of three client instrument ports.
Wavefront sensing is accomplished with six high order sodium laser guide star (LGS) wavefront sensors (WFSs) and
three visible natural guide star (NGS) wavefront sensors. Plus, the control system uses two tip/tilt and one focus infrared
WFSs located in the instruments. In this paper, we describe several optical design challenges we have faced. The science
optics have been redesigned to meet evolving specifications, and the LGS WFS design has undergone multiple
iterations. We present an overview of the optical systems and design drivers, including the current state of each design.