The official answer from both the American Academy of Ophthalmology and the CDC is: don’t nap in your contacts at all. Sleeping in contact lenses, even briefly, increases your risk of eye infection six to eight times compared to removing them before you close your eyes. That said, the reality is that many people doze off with their lenses in, so understanding what’s happening to your eyes and how to minimize damage is worth knowing.
Why Even a Short Nap Causes Problems
Your cornea gets most of its oxygen directly from the air. When you close your eyes, you cut off that supply. A contact lens on top of a closed eyelid creates a double barrier, and oxygen levels drop sharply. When the cornea can’t get enough oxygen, its surface cells switch from normal metabolism to an emergency mode that produces lactic acid as a byproduct. That acid builds up in the middle layer of the cornea, draws in extra water, and causes swelling (called edema).
Even without contacts, your corneas swell about 4% during a normal night of sleep. They recover within a few hours of waking. Adding a contact lens to the equation pushes that swelling higher, and the longer your eyes stay shut, the more lactic acid accumulates. A 20-minute nap produces less buildup than a full night of sleep, but the process starts as soon as your lids close. There’s no established “safe” window where the risk is zero.
Beyond swelling, a warm, moist, low-oxygen environment under a closed lid is ideal for bacteria. Microorganisms that would normally be washed away by blinking and tears can settle against the lens surface and colonize the cornea. This is the pathway to keratitis, the most common contact lens infection, which in severe cases can scar the cornea permanently or even require a corneal transplant.
Your Lens Material Matters
Not all contact lenses block the same amount of oxygen. Traditional hydrogel lenses have high water content but very low oxygen permeability. Research has established that lenses need an oxygen transmissibility of at least 24.1 Dk/t to avoid corneal swelling during daily wear, and 87.0 Dk/t for overnight wear. No hydrogel lens meets that overnight threshold, and some don’t even meet the daily wear requirement.
Silicone hydrogel lenses, introduced in 1999, allow significantly more oxygen through. Some are FDA-approved for extended wear of up to 30 consecutive days, though the FDA notes that eyes should rest without lenses for at least one night after each scheduled removal period. These lenses reduce oxygen-related swelling, but they don’t eliminate infection risk. Sleeping in any contact lens, including those approved for overnight use, still carries that six-to-eightfold increase in infection risk compared to taking them out.
If you know you’re prone to falling asleep with your lenses in (long commutes, movie nights, afternoon fatigue), wearing silicone hydrogel daily disposables gives you a better margin of safety than older hydrogel lenses. But “better” is relative. The safest option remains removal.
What to Do If You Wake Up With Lenses In
If you’ve fallen asleep with your contacts, resist the urge to immediately pull them out. During sleep, lenses can tighten against the cornea as moisture evaporates. Yanking a stuck lens risks scratching the corneal surface.
Start by washing your hands, then blink repeatedly for 10 to 15 seconds. Apply rewetting drops, sterile saline, or multipurpose contact lens solution directly into your eye and blink again. This rehydrates the lens and loosens its grip. If the lens still feels stuck, close your eye and gently massage your upper eyelid until you feel the lens shift. One less obvious trick: if none of that works, place a fresh contact lens on top of the stuck one and blink. The new lens can pull the dried one back to the center of your eye where it’s easier to remove.
After removal, give your eyes several hours without any lenses. Your corneas need time to rehydrate, de-swell, and recover normal oxygen levels. Wearing lenses again immediately compounds the stress.
Signs Something Has Gone Wrong
Most people who accidentally nap in their contacts wake up with dry, slightly blurry eyes that clear up within an hour. That’s uncomfortable but not dangerous. The symptoms that signal a possible infection are different and harder to ignore:
- Pain in the eye that persists or worsens after lens removal
- Unusual redness that doesn’t fade within a few hours
- Blurry vision that continues even after the lens is out and your eyes have rested
- Light sensitivity that makes normal indoor lighting uncomfortable
- Discharge or excessive tearing from the affected eye
- A feeling of something in your eye even after confirming the lens is removed
Any combination of these symptoms after sleeping in contacts warrants a same-day visit to an eye care provider. Keratitis can progress quickly, and early treatment with prescription drops typically prevents scarring. Waiting a few days to “see if it clears up” is where serious, sometimes permanent damage happens.
The Practical Takeaway
There is no duration of napping with contacts that eye care organizations consider safe. A 20-minute nap is less risky than eight hours of sleep, but the infection risk still rises the moment your eyes close with lenses in. If you frequently doze off unexpectedly, keep a lens case and a small bottle of solution in your bag, on your nightstand, and at your desk. The few seconds it takes to pop your lenses out before you drift off can spare you weeks of antibiotic drops or worse.