Contact lenses have become a highly convenient option for people with poor vision. Not only do they provide an attractive option for those who are self-conscious of their image when wearing glasses, but they may be beneficial for people with an occupation or hobbies where glasses are impractical.

However, contact lenses are not a risk-free option; the front of the eye is a highly delicate structure, and if not treated with care, contact lenses can act as a dangerous foreign body. In the most extreme cases, they can cause permanent vision damage. However, being aware of the risks and the best ways to avoid them can help contact lens wearers to get the most out of their use and stay safe in the process.

What are the risks?

Corneal abrasion:

The cornea is the clear window at the front of the eye. If it gets scratched, this is known as an abrasion. This can occur due to poor technique when inserting or removing contact lenses, such as with a fingernail. It may also be caused by the lens itself. Contact lenses that don’t fit the eye properly, or aren’t clean, can also increase the risk. If a scratch occurs on the surface of the eye, it may cause discomfort and/or a gritty feeling and redness. It can also progress to cause an infection, where the whole eye turns red, sore, and you may become sensitive to light. An infected abrasion may develop to form an ulcer at the front of the eye which put the eye at risk of permanent scarring and vision problems.

Corneal infection:

An infection of the clear window at the front of the eye is also known as keratitis. This can occur due to a scratch, or it can result from wearing contact lenses for too long, from improper cleaning, showering or swimming with lenses in, or sleeping with lenses in. This is because all these things risk trapping bacteria and other microbes against the surface of the eye, underneath the contact lens. The longer the lens is in place, or if water becomes trapped underneath it, the higher the risk. Infection at the front of the eye risks scarring and permanent problems with vision if not treated quickly and effectively with antibiotics. Washing your contact lenses with tap water causes a particular risk of infection by a microorganism called acanthamoeba which is very severe, and therefore must be avoided.

Dry eyes:

Wearing contact lenses may cause more mild soreness, watering and irritation of the eyes. This can arise because tears aren’t reaching the surface of the eye due to the contact lens covering it, meaning the eye is more dry than usual. If the eye gets too dry, the lack of protective tear layers puts the eye at risk of damage and scarring.

How can the risks be avoided?

While the risks of contact lenses are serious and the consequences may be severe, taking good care of your eyes and lenses hugely reduces the likelihood of these risks arising. The most important steps to follow are:

  • Ensure a licensed optician has assessed your eyes and fit your contact lenses properly prior to use
  • Avoid wearing contact lenses for more than 8 hours at a time
  • Always remove lenses before sleeping
  • Never wear lenses when showering or swimming, or any activity where water reaches the eyes
  • Thoroughly clean and dry your hands before handling your contact lenses
  • Clean your lenses thoroughly with contact lens solution before and after each use
  • Don’t re-wear single-use contact lenses
  • Never use tap water to clean contact lenses
  • Check your lenses aren’t inside out before inserting them
  • Use lubricating eye drops for dry eyes
  • Don’t apply make-up before inserting contact lenses
  • Attend regular eye tests with the optician.

 

Steps to take if things don’t feel right:

  • If lenses are uncomfortable visit your opticians for a review; don’t continue to wear them but wait until a professional has assessed your contact lenses.
  • If you develop redness, sore eyes, pus, or a vision change, seek a review by a doctor immediately. The quicker you get the right treatment, the greater the chance of avoiding any permanent damage. 

Can my contacts get stuck at the back of my eye?

A final problem to address is: can contact lenses migrate from the front to the back of the eye and get stuck there? A common misconception is that contact lenses can travel and get lodged behind the eye. Fear not – while contact lenses certainly come with risks, it is not possible for contact lenses to travel to the back of an eye with normal anatomy.

There is a thin membrane which covers all healthy eyes, called the conjunctiva, and this forms a pouch just behind the eyelids, which acts as a barrier stopping contact lenses from travelling to the back. If they do get displaced, the lenses can’t travel further than behind the eyelids, so they are usually easy to remove. If you think your contact lens is displaced, you should gently feel over the outside of the eyelid to see if you can feel the lens.  

Always use clean hands. If located, you can try to gently massage the contact lens from behind the lid back to the front of the eye, or use artificial tears applied to the eye to help it float back into place. If you are still unable to move the contact lens, seek a review from an optician or doctor to help you.

  • This article was written by Alice Ditchfield, a junior doctor from Timsbury, Hampshire. She studied medicine at the University of Birmingham and graduated in 2021 before starting work as a junior doctor in London. She is currently teaching medical students in her role as a clinical teaching doctor. She is passionate about medical education and ophthalmology. She will be applying for a training post in ophthalmology this year.