There is a metaphysics to engineering that goes unspoken. One must develop the sense, as an engineer, that the fuzziness of real life can be approximated usefully. Unlike some of our brothers and sisters in the STEM quadrivium (the mathematicians, the scientists), our reality need not be precise nor very accurate at times, so long as it sets out to accomplish what it was designed to accomplish. Our shapes come with tolerances, our rigor with fudge factors. We see the world not how it is but about how it is. Give or take, plus or minus, within such and such a percent. While some of said brothers and sisters can hold in their minds exotic manifolds of multidimensional spaces and still others that can conceive of an elemental particle conflating matter with waves carrying a single discrete unit of energy at the fastest speed possible in the universe (or just about), we just need to know how the LED is going to look when the user is holding it at some angle away from them. We are a practical lot. Not beholden to the right answer, but a right answer, engineers may content themselves with three simple things: a solution, a test, and a better solution.