In a divergent behavior spherical lens, light that strikes parallel to each other is refracted, taking directions that diverge from a single point.
Both thick-edged and thin-edged lenses may differ depending on their refractive index relative to the external medium.
The most common case is that the lens has a higher refractive index than the external medium refractive index. In this case, an example of a lens with divergent behavior is a biconcave lens (with thick edges):
The less common case occurs when the lens has a lower refractive index than the medium. In this case, an example of a lens with divergent behavior is a biconvex lens (with thin edges):