Do eye exercises work?
5 November 2026
07:54
Most contact lens wearers have done it at least once: a late night, a long journey, or a nap on the sofa that lasted longer than planned. Sleeping in contact lenses is one of the most common things we are asked about, and it is also one of the most important habits to break.
This article explains why it matters, what to do if you wake up still wearing your lenses, and the small number of lenses that are designed to be worn overnight.
The cornea, the clear window at the front of the eye, has no blood supply. It takes most of its oxygen directly from the air. When your eyes are closed, far less oxygen reaches it, and a lens sitting on the surface reduces that further.
A cornea that is short of oxygen becomes more vulnerable. At the same time, the closed, warm eye under a lens is a good environment for bacteria. Research has consistently found that people who sleep in lenses not designed for overnight wear have a much higher risk of microbial keratitis, a serious infection of the cornea that can leave a permanent scar and, in severe cases, lasting damage to sight.
A short nap carries less risk than a full night, but the principle is the same: eyes closed for any length of time means less oxygen for the cornea. If you know you are likely to doze, on a flight or a long train journey for example, take your lenses out first or wear glasses for the trip.
Extended wear lenses
Some silicone hydrogel lenses are approved for continuous wear, including overnight, because they let much more oxygen through. They still carry a higher risk of infection than lenses removed every night, so they are only suitable for some people and need closer aftercare. Never sleep in lenses unless your optometrist has fitted them for overnight wear and told you how many nights they can be worn.
Ortho-K lenses
Ortho-K lenses are worn deliberately while you sleep. They gently reshape the cornea overnight, so you can see clearly during the day without glasses or lenses, and they are also used to slow short-sightedness in children. Ortho-K is a specialist fitting with regular check-ups, and the same hygiene rules apply. Read more about contact lens options, including Ortho-K.
Regular aftercare appointments let us check the health of the cornea and catch early signs of oxygen shortage, such as small new blood vessels growing into the cornea, before they cause problems. If you have slipped into the habit of sleeping in your lenses, tell us at your next check-up. We will not judge, and there may be a lens that suits your routine better.
Find out more about our contact lens service in Glasgow and our independent opticians in Glasgow’s Southside.
For a contact lens check-up, call us on 0141 427 4040.
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Yes, unless your lenses are specifically designed and fitted for overnight wear. Sleeping in ordinary lenses greatly increases the risk of a serious corneal infection.
Use rewetting drops until the lenses move freely, remove them gently, wear glasses for the day, and watch for pain, redness, light sensitivity or blurred vision. If any of these appear, get your eye checked the same day.
A short nap carries less risk than a full night, but it still reduces oxygen to the eye. It is safest to take lenses out before sleeping, even briefly.
Some extended wear silicone hydrogel lenses are approved for overnight wear, and Ortho-K lenses are designed to be worn while you sleep. Both need to be fitted and monitored by an optometrist.
Overnight wear can dry the eye, starve the cornea of oxygen and allow infection. Pain after sleeping in lenses should be checked the same day.
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