Our eyes are important organs; we rely heavily on our sense of sight in many aspects of our lives. Perhaps this is why our bodies have evolved to protect our eyes by encasing them in bony cages. This safety feature does have one major drawback; it makes it difficult to see whether a person’s eye has sustained traumatic injury. It can be difficult for emergency room staff to identify patients who have damage to their eyes, but fast treatment could make the difference when it comes to preserving a patient’s vision. Oddly enough, the solution could rely on Vitamin C.

The aqueous humor is the fluid that fills the eyeball, and as it turns out, this liquid has high concentrations of ascorbic acid, more commonly known as Vitamin C. While this compound is found inside the eye, it typically have very low concentrations in tears. If you could “see” that there is a high level of ascorbic acid in a teardrop, you could infer that there may be some physical damage to the eyeball that has caused a leak of the aqueous humor. Researchers at the University of Illinois at Urbana-Champaign decided to tackle this problem.

They created a gel that contains gold nanoparticles. Called OjoGel, the material normally is pale yellow. When it comes into contact with ascorbic acid, however, it shifts to a reddish-brown. The color change intensifies with the concentration of ascorbic acid, providing a quantifiable measure. All it takes is a smartphone and a simple app to determine the color of the gel. It only takes a single tear to provide an adequate sample, and the results are ready right away. This means that emergency personnel without special training could use this system to identify patients with eye injuries. The OjoGel could also be used for post-op eye surgery patients to detect possible leaks from the eyeball.

With further research and clinical trials, this test could help save the vision of patients whose injuries might otherwise go undetected until it’s too late.