Using the radiocarbon dating method and special proteins in the lens of the eye, researchers at the University of Copenhagen and Aarhus can now establish, with relatively high precision, when a person was born. This provides a useful tool for forensic scientists who can use it to establish the date of birth of an unidentified body and could also have further consequences for health science research.

The lens of the eye is made up of transparent proteins called crystallins. These are packed so tightly together and in such a particular way, that they behave like crystals, allowing light to pass through the lens of the eye so that we can see. From conception and up until a human being is 1-2 years of age, the cells in the lens build these crystalline proteins. Once this organic construction work is done, however, the lens crystallins remain essentially unchanged for the rest of our lives. This is a fact that researchers can now put to good use.