But now that eye is shifting towards liquid fuels.

ECONOMIST: Advanced biofuels

New York brand in January launched a new applicator with its Eye Studio Master Duo Glossy Liquid Liner.

WSJ: Clinique Chubby Sticks Are Some New Products Promising Faster, More Precise Makeup

About 4, 000 boat owners are to be given the liquid - which is invisible to the naked eye - to paint their property.

BBC: Boat owners in Hampshire given anti-theft paint

Another challenge is protecting the implant in the eye, since it essentially has to sit in a bath of organic liquid.

WSJ: The Quest to Create A Bionic Eye Gets Clearer