The two eyes of larvae of sunburst diving beetle (Thermonectus marmoratus) have bifocal lens which amazed the scientists. Using two retinas and two distinct focal planes that are substantially separated, the larvae can more efficiently use these bifocals. This enables them to see and catch their prey efficiently. They lose these intricate lenses when they become a beetle.
The scientists first used a microscope to look through the lenses of the two eyes detailed in the research article. They discovered how the lens could make a second image grow sharper. This is something that could only happen with a bifocal. Their findings were confirmed with more research in addition to observing the lens and the two focal planes via a microscope. They saw the bifocal again when they used a method to project a narrow light beam through the lens. This could only be explained by a truly bifocal lens.
The discovery could have uses in imaging technology. The bug inspired imaging devices could be round the corner. The discovery also highlights the importance of conserving our biodiversity.