Lens
A lens is a piece of transparent material that changes the directions of light coming in.
Lenses are in our eyes, and lenses are in magnifying glasses and VR headsets. VR headsets use two lenses, one for each eye.
There are different types of lenses, including fresnel lenses and pancake lenses.
Lenses can be bunched together to form a lens array, which can be used for light field imagery.
VR headset lenses[edit]
VR headsets use biconvex nonequiconvex lenses, meaning they are convex on both sides, but each side has a different curvature from the other.
Biconvex lenses are ideal for positive conjugate image ratios from 0.2 to 5.[1]