Cleopatra's eye make-up smoky eyes

Cleopatra's eye make-up was not just for looks — it also protected her from disease, according to French researchers.

Experts believe that Egyptians applied the eyeliner 4,000 years ago in order to ward off infections.

Lead salts in the make-up helped to protect against eye disease, the study, published in the journal Analytical Chemistry, claims.

The make-up used by the Egyptians sometimes took up to a month to concoct.

Researchers at the Louvre in Paris believe the "smoky eyes" look was for medical reasons as much as aesthetics.

At low levels, salts produce nitric oxide, which boosts the immune system to fight off bacteria that can cause eye infection.

"In stimulating non-specific immunological defences, one may argue that these lead compounds were deliberately manufactured and used in ancient Egyptian formulations to prevent and treat eye-illnesses by promoting the action of immune cells," the researchers said.

It is also thought that galena, the natural mineral form of lead sulphite, was used as eye make-up and that it has antiseptic and fly-deterrent properties as well as protecting the eyes against intense sunlight.