With a wavelength of 550 nanometers typically used, that means most microscopes can only see about 0.2 micrometers (or about the width of a bacterium), according to Abbe.
But the best thing about limits in science is that they can almost always be surpassed. And when you do that, you usually get a Nobel Prize. This year, the Nobel Prize in Chemistry was awarded to three scientists for their work in circumventing the optical resolution limit. That means they made microscopes even more micro. They've actually gone nano.
You see, a maximum resolution of 0.2 micrometers may seem pretty small, but it's quite large when it comes to observing the tiny, individual molecules in the human body. A small molecule can be just one nanometer long.
With the help of these nanoscopes, researchers have been able to visualize molecules such as those created in synapses in the brain. They can also track protein buildup in numerous degenerative diseases, such as Alzheimer's or Parkinson's.
In fact, nanoscopy can even be used to visualize the individual proteins in fertilized eggs.