Feeling tired and wanting a quick nap is common. For contact lens wearers, this raises a question: is it safe to nap with contacts in? Eye care professionals generally advise against napping or sleeping with contact lenses. Understanding why is important for maintaining eye health and preventing complications.
The Risks of Napping with Contacts
Leaving contact lenses in while napping significantly reduces oxygen supply to the cornea. When eyes are open, the cornea receives oxygen directly from the air, but contact lenses act as a barrier. During sleep, closed eyelids further limit oxygen access and reduce tear production. This oxygen deprivation, known as corneal hypoxia, can weaken the cornea’s natural defenses.
A low-oxygen environment, combined with warmth and moisture under a closed eyelid, creates an ideal breeding ground for bacteria. This increases the risk of eye infections, such as microbial keratitis. Microbial keratitis is an inflammation of the cornea that can cause pain, redness, blurred vision, and sensitivity to light.
If left untreated, severe infections can lead to corneal ulcers, which are open sores on the cornea. Corneal ulcers are painful and can cause permanent vision impairment or even blindness. Beyond these serious risks, napping with lenses in often results in immediate discomfort upon waking, including dry eyes, redness, and irritation, as the lenses can dehydrate and stick to the eye surface.
What to Do After Napping with Contacts In
If you accidentally nap with your contact lenses in, avoid immediately pulling them out. Eyes and lenses are likely dry, and forcing removal can cause irritation or even damage to the corneal surface. Instead, blink several times to encourage natural tear production to rehydrate the lenses.
If blinking isn’t enough, use rewetting drops or artificial tears to lubricate your eyes. Apply drops and wait a few minutes, allowing the lenses to rehydrate and move more freely. This makes them easier and safer to remove. Once rehydrated, gently remove them as you normally would.
After removal, discard daily disposable lenses. For reusable lenses, clean and disinfect them thoroughly according to manufacturer’s instructions; consider discarding them if they feel compromised or overly dry. Give your eyes a break by wearing glasses for several hours or the rest of the day for recovery. Monitor your eyes for irritation, redness, pain, or blurred vision, and contact an eye care professional if symptoms persist or worsen.
Contact Lens Types and Oxygen Permeability
The cornea requires a continuous supply of oxygen for health and transparency. Contact lenses sit on the corneal surface and can impede this oxygen flow to varying degrees. The ability of a contact lens material to allow oxygen to pass through it is measured by its Dk (diffusion constant for oxygen) value, and lens thickness, it’s expressed as Dk/t (oxygen transmissibility). A higher Dk/t value indicates greater oxygen permeability.
Contact lenses are categorized as daily disposables and reusable lenses. Daily disposables are for single-day use and offer good oxygen permeability for awake wear, but not for sleep. Extended wear lenses are made from breathable silicone hydrogel materials, which allow more oxygen to reach the cornea. These materials have higher Dk/t values.
While extended wear lenses have higher Dk/t values and are approved for some overnight wear by eye care professionals, this does not mean they are universally safe for sleep. Even with high oxygen permeability, the closed eyelid during sleep further restricts oxygen, and reduced tear flow can still lead to issues like lens dehydration and bacterial accumulation. Research shows that sleeping in contact lenses increases the risk of eye infections compared to daily wear, even with extended wear lenses. Always adhere to your eye care professional’s recommendations for your lens type and wear schedule, as they consider your individual eye health and lifestyle.