Designing optical systems is never an easy task; even perfectly designed systems contain optical aberrations. The trick is in understanding and correcting for these optical aberrations in order to create an optimal system. To do so, consider the types of aberrations present in optical systems.

Optical aberrations are deviations from a perfect, mathematical model. It is important to note that they are not caused by any physical, optical, or mechanical flaws. Rather, they can be caused by the lens shape itself, or the placement of optical elements within a system, due to the wave nature of light. Optical systems are typically designed using first-order or paraxial optics in order to calculate image size and location. Paraxial optics does not take into account aberrations; it treats light as a ray and therefore omits the wave phenomena that cause aberrations.