Oxygen from the air is vital to keep the cornea (the front clear surface of the eye) healthy.  The majority of modern soft contact lenses allow sufficient oxygen through the lens for daily wear.  When you are asleep, the amount of oxygen available to the eye is reduced as your eyes are closed and this can cause problems for the eyes.  As the vast majority of contact lenses currently prescribed are for daily wear (either daily disposable or reusable lenses that are stored in disinfecting solution overnight) it is important that these are removed prior to sleep.  This is because the use of daily wear lenses overnight increases the risk of complications such as developing a corneal ulcer (which can be painful).  This is thankfully a very rare condition and while treatable in many cases it can cause scarring which may have a long-term effect on your vision. 

There are some contact lenses that are approved for overnight use, known as extended wear.  With overnight use, the risk of complications and developing a corneal ulcer is higher than with daily wear.  For this reason, only an eyecare professional can assess your suitability for such mode of lens wear. And if so explain you the risks and ensure you are fitted with the most appropriate lens.

It is likely that even the most careful wearers have fallen asleep with their daily wear contact lenses during an unplanned nap or overnight if they forget to take them out.  So, what should you do?  Once you have been asleep in your contact lenses, your eyes may feel dry and the lenses may be harder to remove than usual.  Therefore, you could wait a few minutes before attempting to remove them, or the use of rewetting drops (suitable for use with contact lens wear) may also help.  Once removed, leave your lenses out for at least a few hours.  Ensure that your eyes look and feel good and that your vision is clear with your spectacles.  If you are unsure or if you notice any redness, pain or reduced vision seek immediate advice from your eye care professional.

Careful compliance with lens wear and care will help to minimise the risk of any potential infections or other complications – including:

  • Do not sleep in your lenses unless wearing a suitable extended wear contact lens product which has been advised and fitted by your eyecare professional. 
  • Always wash your hands thoroughly with a mild soap, rinse carefully and dry properly with a lint-free towel before handling your lenses.
  • If wearing reusable lenses ensure you clean them properly in accordance with the manufacturer’s instructions and always store your lenses in fresh solution. 
  • Never use tap water to rinse your contact lenses or contact lens case.  Always use the disinfecting solution advised by your eyecare professional.  Also, remember to change your case regularly in line with instructions accompanying your disinfecting solutions.  
  • After inserting your contact lenses dispose of the solution in the case and allow the case to air-dry.
  • Insert your lenses before putting on make-up. Oily cosmetics, soaps, lotions or creams can damage lenses and make putting them in more difficult.

Ensure you have your eyes checked regularly by your eyecare professional, in particular if you wear lenses that were prescribed to you to use overnight, and always remove your lenses and seek advice from your eyecare professional if you have any problems with your eyes during contact lens wear.