When most people think of cells, they picture the microscopic building blocks of everything that surrounds us, and certainly not something that they could hold or even see.

One of the largest single-celled organisms on Earth, however, can be about the size of the human eye.

In fact, it is known as the ‘Sailor’s Eyeball’ because of its size and the fact that it can be found floating in the oceans in many tropic and sub-tropic areas.

These blob-like algae are scientifically known as Valonia Ventricosa, and can be as small as the head of a pin or as large as a human eye. They can get so big because of the fact that the space inside the cell wall gets far bigger than with other types of cells.

If you happen to find one of these interesting things in the ocean, you may be tempted to pop it, which can be done surprisingly easily.

Once popped, the algae might actually form into multiple new organisms over time.

This is because while it is a single-celled organism, it has multiple cell nuclei within its cell wall. This is called a coenocytic organism.

As with many other types of algae, the sailor’s eyeball can come in multiple different colors. They are most commonly seen as a dark green or black, but can also be very silvery. The color is based on the structure of their cell wall’s cellulose crystals.

They can also be found at many different depths within the ocean. One was even found 3.1 kilometers (2 miles) under the ocean. It was attached to the ocean floor.

It was seen during a NOAA Ocean Exploration life feed, and one of the researchers commented on the fact that its cell wall had a hole in it, saying that it looked like:

“Something tried to get in…or get out.”

Whether they are attached to rocks at the bottom of the ocean, or floating free along the currents, these simple organisms are always a fun surprise when seen.

While it can be tempting to pop them, it is best to avoid as it is generally best to avoid interfering with the natural life cycles of nature.

If you would like to see a sailor’s eyeball in the ocean, check out this quick video:

If you find a sailor’s eye in the ocean, don’t pop it.

Thought that was fascinating? Here’s another story you might like: Why You’ll Never See A Great White Shark In An Aquarium