The heavy eye make-up favoured by ancient Egyptians such as Cleopatra may have had medical as well as aesthetic benefits, French research suggests.

The study, published in the journal Analytical Chemistry, suggests it helped to protect against eye disease.

The key appears to be lead salts contained in the make-up.

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