SLAPPING on a bit of concealer and mascara helps many of us feel more confident. But how and where we apply our make-up can have "dire" health consequences - particularly for our eyes, experts warn. Not only can we end up with blurry vision and crusty or sticky discharge, we also risk losing our eye sight altogether.

Nimmi Mistry, an optician at Vision Direct , said: "The make-up habits many of us are guilty of could lead to sight loss." From sleeping in mascara to sharing eyeliner with your pals, the eye expert reveals the five most common mistakes - and what can happen if you keep doing them. 1.

Doing your make-up on the go "Applying make-up on the train, bus or Tube is common practice for many," Nimmi said. "For some, it is a way to transition from day to night to go out, while for others it is a chance to save time on the morning commute. "However, this seemingly innocent act could have dire consequences for your eyesight.

" A recent study swabbed London Tube lines to reveal the bacteria lurking on the seats and handrails, and the results were grim. Researchers discovered that seats on the Victoria Line housed "exceptionally high" levels of E. coli - 160,000 colony-forming units (CFUs).

Most read in Health While on the Metropolitan Line, there were traces of Pseudomonas aeruginosa (400 CFU), Faecal Streptococci, and enterococci on the seats (960 CFU) and poles (80 CFU). Pseudomonas aeruginosa was also found on an Oxford Circus escalator handrail (720 CFU), Northern Line se.