By: Nour Hany

How many of us take tears for granted? We shed salty water drops from each eye every now and then, but have we ever really thought of their significance? As a matter of fact, while you are reading this now, each of your eyes contains seven microliters of tears, which equals about a tenth of a drop of water. The salty water we have works as filtered blood, delivering oxygen and nutrients to our eyes, healing injuries, removing waste, and serving as the first line of defense against pathogens.

Tear Testing

Various chemicals in the blood can be found in tears, some of which work as markers of illness; such as enzymes telling us of possible liver disease, or glucose that signals diabetes. These diseases and many more are the reason why doctors ask for blood tests. If these indicators of disease already exist in tears, it means that, in the near future, not only doctors may be able to trace these diseases, but you will also be able to find these indicators in your tears by yourself!

Farewell, Mammograms

Markers of many of the most devastating and common diseases have been found in tears, including Parkinson’s disease, diabetes mellitus, cancer, cystic fibrosis, and multiple sclerosis. Moreover, scientists are currently working on finding a way to use these markers to diagnose Alzheimer's disease.

When it comes to devastating diseases, breast cancer stands at the front line, even though it is highly curable if diagnosed early; still, it terrifies many people, especially in its testing process. Recently, a new technology called TearExo has been developed to screen breast cancer, using patients' tears they collected themselves. This allows earlier detection of malignancy, in a much better method than mammograms. Moreover, it highly reduces the cost of doing other tests, as patients only need to collect their tears and simply mark their illness, whether by themselves or with the help of their doctors.

It is also possible for tear testing to make an impact on the COVID-19 pandemic; this testing is usually done with blood, but coronavirus RNA was also found in tears and we can also measure the antibodies from tears. It means that each individual could do the test at home by themselves, as it does not involve any needle interference.

All that is only the beginning in a wide world of possibilities presented by our own tears.

Reference

www.scientificamerican.com