The video below depicts the inner ear of a zebrafish — you know, that little inch-and-a-half (4-centimeter) striped thing you see in pet store fish tanks? Suffice it to say, the objects in this footage are very, very small. Here, a fiery yellow immune cell rolls on through gobbling up bright-blue particles of sugar.

Where's your 2D cell diagram now? The immune cell morphs and stretches as it wriggles through the organ, looking nothing like the flat circle we're all used to.

Scientists have been able to see living cells under the microscope for centuries, but for most of that time, you had to capture them with the cells isolated on glass slides to keep the images from being blurry. That's not exactly their natural state: Cells are more likely to cluster in wriggling groups, which are about as easy to photograph as a small child at a birthday party. Even new imaging technology is too slow to follow the action in 3D, or too bright to really show what the cells look like in their natural environments. That's a problem, says physicist Eric Betzig, the group leader behind this breakthrough. "This raises the nagging doubt that we are not seeing cells in their native state, happily ensconced in the organism in which they evolved."

There's another field that deals with issues of blurry images: astronomy. The churning atmosphere above our heads is what makes the stars appear to twinkle, and that poses a problem for astronomers using ground-based telescopes. To fix that, they use a method called adaptive optics, which relies on mirrors that computers can deform at will to correct these atmospheric distortions in real time. To do that, they need to have a bright reference star the computer can use to measure the blurring — but barring that, they can just shine a laser where a star would be and measure the blurring of that instead.

So Betzig and his team took a page from their book, combining adaptive optics with a technology called lattice light sheet microscopy. This imaging technique sweeps an ultra-thin sheet of light through the cell, building a high-resolution 3D movie from the 2D images it takes in real time. They aimed one adaptive optical system at the side view to maintain the lattice light sheet's illumination and aimed another adaptive system from above. Then, they could shine their reference laser through either pathway to let the optics self-correct and achieve a super-sharp 3D image.

We've had this technology at our fingertips, but it's been too complicated and expensive to be practical, even for advanced research labs. Betzig wants to change that. "Technical demonstrations and publications don't amount to a hill of beans," he says. "The only metric by which a microscope should be judged is how many people use it, and the significance of what they discover with it." While his current microscope fills a 10-foot-long table, his team is working on a smaller one they hope will fit on a small desk and sport a more reasonable price tag. In the true spirit of science, however, the team will make their plans freely available to other scientists who want to build their own microscopes.

In the meantime, feast your eyes on the other footage the microscope captured.