“If a light beam hits the lens and gas is absorbed ... Using 3D-printed fused silica templates, we show that concave as well as convex lens structures can be obtained at high precision by ...

"We purposely added optical blurring to the beams of light used for this 3D printing ... using it to make a millimeter-sized plano-convex optical lens with an imaging performance similar to ...

A lens is a specially shaped pieces of glass or transparent plastic, that is used to focus light. A convex lens is made from a transparent material that bulges outwards in the middle on both sides.