Contact lenses are widely used medical devices that correct vision by resting directly on the eye’s surface. For the millions of people who wear them daily, the possibility of falling asleep for a quick rest raises questions about eye safety. Understanding how these lenses interact with the delicate ocular environment during periods of rest is important for maintaining eye health and preventing complications.
The Quick Answer: Contact Lens Napping Safety
Taking a nap while wearing contact lenses is not recommended by eye care professionals. Even a short period of sleep significantly increases the risk of eye irritation and infection. This caution applies to nearly all types of lenses, including those intended for daily wear. The eye’s natural processes change during sleep, making it a poor environment for lens wear. The safest practice is always to remove contacts before resting, regardless of the nap’s duration. Wearing lenses during sleep raises the likelihood of acquiring a severe eye infection by six to eight times.
The Biological Risk of Sleeping in Contacts
The primary concern when sleeping in contacts relates to oxygen supply for the cornea. The cornea, the transparent front dome of the eye, relies on oxygen absorbed directly from the air, as it has no blood vessels. When the eye is open, tears and the atmosphere provide this oxygen, but when the eyelids close, the oxygen supply is naturally reduced. Adding a contact lens creates a physical barrier, further restricting the limited oxygen that permeates through the closed eyelid. This lack of oxygen is known as hypoxia and can cause the cornea to swell, weakening its protective outer layer of cells.
A compromised corneal surface is more susceptible to invasion by microorganisms. The warm, dark, and moisture-rich environment under a closed eyelid is an ideal breeding ground for bacteria. Lenses can trap bacteria and debris against the corneal surface, allowing them to multiply rapidly. This scenario increases the risk of microbial keratitis, a serious infection of the cornea that can result in permanent vision impairment or scarring.
Navigating Different Lens Types
Contact lenses are categorized based on their intended wearing schedule, which is determined by the material’s oxygen permeability. Standard daily wear lenses are designed to be worn only during waking hours and must be removed before any sleep, including naps. These lenses transmit less oxygen compared to newer materials.
Extended wear lenses, often made with breathable silicone hydrogel materials, are formulated to allow a greater flow of oxygen to the cornea. These lenses are the only type approved by the Food and Drug Administration (FDA) for overnight wear, sometimes for up to a month, depending on the product. However, FDA approval is not a guarantee of safety, as sleeping in any lens type still elevates the infection risk compared to not wearing them.
A person should only consider sleeping or napping in extended wear lenses if explicitly prescribed for that purpose by their eye care specialist. Even with these materials, the overall risk of developing an infection remains elevated compared to removing the lenses nightly. Daily disposable lenses, which are replaced every day, are considered the safest option, as they eliminate the risk of protein and lipid buildup that occurs with repeated use.
What to Do If You Accidentally Nap
If you wake up and realize you have accidentally slept in your contact lenses, resist the urge to remove them immediately. During sleep, your eyes produce fewer tears, causing the lenses to become dry and adhere tightly to the cornea. Attempting to pull off a dry, stuck lens can cause a painful scrape or abrasion on the corneal surface.
The first step is to rehydrate the eye and the lens by blinking or using sterile saline or re-wetting drops designed for contact lenses. Wait a few minutes after applying the drops, allowing the lens to move freely on the eye before attempting removal. Once the lens is lubricated, wash your hands and gently take the lens out as you normally would, discarding the pair if they are daily disposables.
It is advisable to wear glasses for the rest of the day to let the eye recover and allow the cornea to receive maximum oxygen. If you experience persistent symptoms such as redness, pain, increased light sensitivity, blurred vision, or discharge, contact an eye care professional immediately. These symptoms may indicate the onset of a serious infection.