People are sometimes intrigued or appalled by the types of goldfish that have strange eyes, especially the Bubble Eye varieties. No matter your reaction, you can’t stop looking at Bubble Eye goldfish. Bubble Eyes are odd-looking goldfish because of the large fluid-filled sacs that sit under the eyes that move around as they swim. The sacs look like water wings, but what would a fish need with water wings? Bubble Eyes have no dorsal fin (top fin), which makes the sight of their giant eye sacs even more bizarre. Bubble Eyes need a safe tank environment, without aggressive tankmates and sharp tank decorations, both which may damage or puncture the bubbles. Damaged bubbles will probably grow back but it will be stressful and painful for the fish and distressing for you, the loving owner. Bubble Eyes are also very tame, calm goldfish so for that reason as well, they are good tank mates only for non-aggressive goldfish.