Scientists have developed a novel optical lens that is much thinner and lighter than conventional lenses, an advance that could flatten the unsightly "camera bumps" in smartphones and lead to longer-flying drones.

While conventional lenses for smartphone cameras are a couple of millimeters thick, the new lens is only a few microns thick, or a thousand times thinner than regular lenses, according to the study published in the journal PNAS.

"Our lens is a hundred times lighter and a thousand times thinner, but the performance can be as good as conventional lenses," said Rajesh Menon, an associate professor at the University of Utah in the US.

A conventional curved lens takes light that bounces off an object and bends it before it ultimately reaches the camera sensor that forms the digital picture.

However, the new lens has many microstructures, each bending the light in the correct direction at the sensor.

The team has developed a fabrication process with a new type of polymer along with algorithms that can calculate the geometry of these microstructures.

"You can think of these microstructures as very small pixels of a lens. They are not a lens by themselves but all working together to act as a lens," Menon said.

The result is a lens that is flat instead of curved and more than 20 times thinner than a human hair with the added capability of being used in thermal imaging to see objects in the dark, the researchers said.

While this could ultimately produce smartphone cameras with no bump, it could also give them the ability to take thermal imaging to look for heat signatures, they said.

However, a more immediate use for this technology would allow lighter military drones to fly longer for night missions or to map forest fires or look for victims of natural disasters, the researchers noted.

Soldiers in the field could carry much lighter night vision cameras for longer durations, they said.

Menon said this new lens could also be cheaper to manufacture because the design allows to create them out of plastic instead of glass.