Lens elements are a few millimetres thick but many of them use several which add up so that a thin phone has not got the room to house all of them. This has resulted in a camera bump, which those who like things flat, find gravely offensive.
But a team of electrical and computer engineering researchers at the University of Utah have succeeded in creating a new type of optical lens that measures just a few microns thick, or about a thousand times thinner and one hundred times lighter than what you'll find in smartphones today.
The lens the researchers created is made up of innumerable tiny microstructures, imperceptible to the human eye, and strategically positioned so that each one bends and redirects light towards a camera's sensor.
When they're all working together, they produce the same results as a single curved element does. Manufacturing the lenses required the team to develop a new fabrication process, a new polymer, and custom algorithms to calculate the shape and position of each microstructure. But the resulting lens can be completely flat, and made of lightweight plastic. The study has been published in the Proceedings of the National Academy of Sciences.