Can lens designs be brute-force computed to create optically precise equipment? It seems lens design hasn't changed much over the last 50 years or so with many older manual lenses still very much being used today. Can the order, distance between and type of lens elements be brute force calculated with known values for IOR to find a design with minimal aberration and distortion?
If this is possible, is it being implemented?
 A: Optics design has definitely changed in the past years. Lens designs for precision lenses, especially those dealing with powerful and precise lasers, are still a hot topic of development. If I understand what you mean by "brute force", then the answer is definitely yes. Check out "Zemax" software for an example of this @ www.zemax.com. A large part of the difficulty in lens design is not the theoretical design of a system, but the actual precision construction of the designed system.
A: Can the order, distance between and type of lens elements be brute force calculated with known values for IOR to find a design with minimal aberration and distortion?
Sure. Actually the nicest implementations for me are the so called adaptive optics, like the spatial light modulator and the deformable mirrors.
The principle is to have several physical microscopic objects which can change the phase profile locally on a wavefront. These "pixels" can be tiny mirrors mounted on piezo actuators in a grid, or a deformable reflective membrane which is pushed and deformed by a similar grid of actuators, or pixels filled with liquid crystals which change index as a function of applied voltage.
The brute force is used this way: 1) you create an image using, among other optics, the adaptive element. 2) aberrations need to be quantified in the image 3) a PID algorithm changes the pattern of positions for the small actuators (or pixel voltage for liquid crystals) to optimize the image minimizing the aberrations.
The final pattern which optimizes the image depends on everything on the optical path and it's found after several iterations.
