We knew that some bacteria, including the cyanobacterium Synechocystis, can detect and move towards light, which is important in its oceanic environment. However, rather than doing so by responding to a gradient in light intensity as many other organisms, Schuergers et al. report in eLife that Synechocystis cells act as spherical microlenses. When a light is shone at the cell, an image of the light source is focused at the opposite edge. Photoreceptors respond to the focused image of the light source, providing the cell with cues to move towards the light.
In essence, these tiny guys are light-loving, microscopic eyeballs!