It’s called vitrious humor. It’s a clear, gel-like material that gives the eye its shape. It’s found between the lens, in the front of the eye, and the retina, in the back. It’s mostly water, but there’s also a small amount of collagen and hyaluronic acid, which you may have heard of from beauty products.
The eye also contains aqueous humor, another gel-like substance. It’s found in pockets near the iris, the colorful part of the eye surrounding the pupil. The composition of aqueous humor is similar to blood plasma, but with way less protein.
And that’s the deal with the liquid in your eyeballs!