A report from British and German experts have identified cells which act as a microscopic eyeball for bacteria.
Conrad Mullineaux, Professor of Microbiology from Queen Mary University of London’s School of Biological and Chemical Sciences and lead author on the study, said: “The idea that bacteria can see their world in basically the same way that we do is pretty exciting.”
The experts looked at a species of cyanobacteria known as Synechocystis.
Cyanobacteria are found in their masses in fresh water, or make-up the green slime that is found on rocks and pebbles.
It is one of the first species on Earth, having evolved around 2.7 billion years ago.
They survive through photosynthesis, which has piqued scientists curiosity on how they sense light, with the minuscule bacteria being studied for more than 300 years.
Previous studies have indicated that cyanobacteria possess photosensors which perceive the source of light and move towards it.
The latest examination, of which the results are published in eLife, revealed that the photosensor cell body acts as a spherical lens, and as light hits it, it refracts to a point on the other side of the cell – much like the process with the human eye.
Mullineaux added: “The fact that bacteria respond to light is one of the oldest scientific observations of their behaviour.
“Our observation that bacteria are optical objects is pretty obvious with hindsight, but we never thought of it until we saw it. And no-one else noticed it before either, despite the fact that scientists have been looking at bacteria under microscopes for the last 340 years.”