Contact lenses are pretty powerful. And not just in the good sense. Yes, they correct your vision without the use of bulky frames. But they also alter the bacteria in your eye.

As reported by WebMD, the act of putting contact lenses – a foreign material – into your eye is not a “neutral act.” It is hypothesized that this introduction of a foreign substance to the surface of your eye is to blame for contact-wearers being more prone to eye infections.

The potential infections aren’t anything pretty, either; bacterial keratitis is one of them, and it can cause pain, reduced vision, light sensitivity and discharge from your eye. The infection can even leave a scar that could affect your vision.

The bacteria that causes this infection is known as pseudomonas aeruginosa and, aside from being incredibly difficult to pronounce, it can also affect areas of the body like the skin, bones and joints, according to Medscape.

All this is probably not much of a surprise to you if you know anything about how dirty contact lenses can get. If you want to get caught up on the dirty details, check out this video from Gross Science.

Now, don’t take all this to mean that you’re bound to a glasses-only existence for the rest of your horrible eyesight days – It is preventable if you take good care.

Here are a few tips I’ve found from the Canadian National Institute for the Blind on preventing infections caused by contact lenses:

  • Wash your hands thoroughly before handling your lenses.
  • Clean your lenses regularly using a solution meant specifically for contact lenses. Ask your eye doctor for recommendations.
  • Store your lenses in a proper case and keep the case clean.
  • Replace your lens case every three months.
  • Ask your eye doctor how often you should replace your lenses. If you have disposable lenses, change them daily.
  • Do not sleep with your lenses in.