Eyeliner on inner lid can cause vision problems

The study by a University of Waterloo scientist Dr. Alison Ng, which is the first to prove that particles from pencil eyeliner move into the eye, used video recordings to observe and compare the amount of eyeliner particles that migrated into the tear film - the thin coating protecting the eye - after applying makeup in different styles.

Within five minutes, between 15 and 30 per cent more particles moved into the eye's tear film when subjects applied eyeliner to the inside of the lash line, compared to outside it. The makeup also moved more quickly into the eye when eyeliner was applied inside the lash line.

As time passes, the amount of makeup entering the tear film steadily drops and by two hours, there was a negligible amount of eyeliner left. However, Dr. Ng and her colleagues say eyeliner can alter the tear film, adding to discomfort.

Eyeliner ingredients commonly include waxes, oils, silicones and natural gums to help eyeliner stick to eyelids and last for prolonged periods. It has to adhere through blinking, sweating and the secretion of natural oils.

Resulting complications include irritation and redness, introduction of harmful bacteria from the eyeliner, and in some cases, eye infections or blur red vision.

Dr. Ng said that people who wear contact lenses were most likely to notice some problems, adding that pencil eyeliner was thoroughly sharpened, it gives a fresh tip which can help prevent infection.

The results are published in the journal Eye and Contact Lens Science and Clinical Practice.