Scientists recently looked into the structure of a single-celled organism eye, which is thought to have evolved to see its prey clearly. The one-celled organism studied during the study is known as a warnowiid dinoflagellate.

The research paper published in Nature on Wednesday stated that the eye of marine plankton looks like a dark purple spot on the plankton.

Greg Gavelis, lead author of a paper, said, “It's an amazingly complex structure for a single-celled organism to have evolved. It contains a collection of sub-cellular organelles that look very much like the lens, cornea, iris and retina of multicellular eyes found in humans and other large animals”.

Researchers affirmed that when the plankton was seen for the first time in 1920s by marine biologists, they mistaken the eye for prey consumed by the plankton. They said this happened because of the complex nature of the eye.

It is still unclear how the plankton uses its ocelloid. The plankton hunts other dinoflagellates most of which are transparent, said experts.

The authors of the research paper said that the ocelloid may help the plankton detect its prey by enabling them to notice the shifts in light as it passes through the prey. According to authors, there are possibilities that the ocelloid then informs the plankton about which direction to hunt in.

The researchers obtained warnowiid dinoflagellates off the coasts of British Columbia and Japan. They sequenced their DNA before they started examining them by using highly sophisticated microscopes that can assemble three-dimensional images of structures that are smaller than cells.