Ray optics

Ray optics is a method of the study of optics where light is represented as rays.

In reality, light is more wavy, but approximating it as straight lines makes calculation and computation much more efficient.

There are some things that ray optics is not sufficient for, for example sub-wavesize structures and simulation. Also ray optics does not take into account diffraction.

Ray optics was thought of by Greeks a long time ago in a simpler form. It was thought by some that rays of light emanated from the eyes and out into the world. This is false, but the concept of rays has carried through.

Ray optics can be useful for studying basic optical systems, for example a basic 2010s-era VR headset.