It’s tough to deliver medication quickly and precisely to different parts of the eye. Traditionally medicine for conditions like glaucoma or diabetic macular odema is injected into the eye or dropped onto the surface and left to diffuse slowly throughout. This delivery method isn’t always accurate and means the entire eye receives the drug. The process can be slow irritating and painful for the patient. Researchers wanted to build tiny delivery vehicles they could drive to deliver cargo quickly to specific parts of the eye particularly through the dense jelly called the vitreous humour. So they use nano scale 3d printing to create small spiral-shaped delivery bots. The bots were nearly 200 times smaller than the diameter of a human hair. Their tiny size and a nonstick coating made it easier for them to pass the tight matrix of the vitreous humour. The spiral bots also contained magnetic material which meant the researchers could drive them forward backward left or right with a magnetic field. The scientists injected a solution containing around 10,000 of the spiral bots into eyes collected from pigs and put the eyes in a magnetic field. They used imaging techniques and dissection to see if the bots have been able to pass through the eyeball’s jelly all the way to the back where the light the sensing retina lives. The bots were able to deliver their cargo to the right place in much less time than simple diffusion would allow. Next the researchers are planning to test the spiral bots in a living animal’s eye. It will be years before any humans have tiny spiral robots delivering drugs to the back of their eyes. But the work is a step forward in building controllable vehicles to aim medicine at precise targets in sensitive areas of the body.