JERUSALEM, July 19 (Xinhua) — An Israeli new study on the complexity of the structure of a fish’s eye could help treat kidney stones and gout disease, the Weizmann Institute of Science in Israel said Thursday.

The study focused on the sophisticated vision systems and the great precision and complexity of a zebrafish’​s eye iris.

The researchers wanted to know how the fish’s eye could block unwanted light, like the humans’, and how it can return the light as a mirror to create camouflage.

Using a computerized micro-tomography (microCT) system, the researchers obtained a comprehensive picture of the eye, and with a scanning electron microscope (cryo-SEM), they focused on the sections of the iris.

The researchers found three layers in the fish’s eye iris, each of which can return unwanted light with a different specific function.

The outer crystalline layer returns light mainly at blue and green wavelengths in the water, which are suitable for camouflage. The second layer discovered disperses the light, and the third one acts like a “black screen” that swallows the rays that managed to slip through the other two layers.

Understanding how fish controls the development of crystals in their eyes may help treat diseases such as gout and kidney stones, as crystals of a similar substance, known as uric acid, are formed in unwanted places in the cases of gout and kidney stones, the researchers said.