Non-Sequential Lens Design (NLSD) has various challenges that need to be overcome. One benefit of NLSD is that tracing non-symmetric systems is quite simple. The downfall of NLSD is when the Chief ray is occluded. In sequential designs, the Chief ray is still calculable even if it is occluded, because it is just assumed that it will go to the next surface. In NLSD, because there is no known sequence the computer must determine what the proper sequence is, which can be challenging. Luckily there are various clever techniques which we can use to ensure that we properly represent optical systems even without the Chief Ray, which we will employ to ensure we can deal with this particular system and perform wavefront analysis.
