Scientists have developed a 'death test' that can tell how many years people have left on the planet.

A painless laser pulse is applied to the surface of the skin through a wristwatch-style device. The simple, non-invasive test is the first of its kind in the world.

This test calculates how a person's body will decline with age by analysing endothelial cells. These cells line the smallest blood vessels in the body and respond to other activities elsewhere in the body.

By measuring the oscillations within the capillaries, scientists claim they can calculate the length of time before someone dies. They can also test for life-threatening diseases including cancer and dementia.

The result is graded from 0 to death to 100 for optimum functioning. The more data added, the more accurate the predictions become.

A user-friendly version of the system is expected to be finalised within the next three years when it becomes available to doctors.

The test, funded by medical charities and government research grants, is pioneered by Aneta Stefanovska and Peter McClintock, physics professors from Lancaster University.

Stefanovska, who is credited with inventing endothelial reactivity, told the Sunday Times: "I am hoping we will build a database that will become larger and larger, so every person measured can be compared against it. We will then be in a position to tell them the values [that] predict a certain number of years."

There have been other recent breakthroughs in medical research to predict how long people will live. In another study, A revolutionary new blood test could tell you how long you will live, and how quickly you will age, thanks to a chemical 'fingerprint' in the blood.

It could lead to the development of powerful new treatments for age-related conditions such as bone problems and heart disease.

Professor Tim Spector of King's College London, told the Daily Mail: "Scientists have known for a long time that a person's weight at the time of birth is an important determinant of health in middle and old age, and that people with low birth weight are more susceptible to age-related diseases.

"So far the molecular mechanisms that link low birth weight to health or disease in old age had remained elusive, but this discovery has revealed one of the molecular pathways involved."