Eye care professionals generally advise against wearing most standard contact lenses overnight. This recommendation stems from physiological factors and potential health complications that can arise when lenses remain in the eyes during sleep. This article explores the reasons for this guidance, outlines specific risks, discusses exceptions like extended wear lenses, and provides steps to take if lenses are accidentally worn overnight.
Why Overnight Wear is Discouraged
Sleeping with contact lenses restricts the natural oxygen supply to the cornea. This reduced oxygen, known as corneal hypoxia, can compromise the cornea’s health. When eyelids are closed during sleep, the eye receives even less oxygen from the atmosphere, exacerbating this issue.
Contact lenses can also trap debris, microorganisms, and protein deposits against the corneal surface. The warm, moist environment under a closed eyelid becomes an ideal breeding ground for bacteria and other pathogens. This combination of reduced oxygen and increased microbial presence significantly elevates the risk of eye problems.
Specific Risks to Eye Health
Wearing contact lenses overnight can lead to several serious eye conditions. Microbial keratitis, an infection of the cornea, is a significant concern. Symptoms include eye pain, redness, blurred vision, and light sensitivity, and if untreated, it can result in permanent vision impairment or blindness. Studies indicate that sleeping in contacts increases the risk of microbial keratitis by over five times.
Corneal ulcers, which are open sores on the cornea, also pose a substantial risk. These painful conditions can lead to significant vision loss or permanent damage if not promptly treated. Another condition is giant papillary conjunctivitis (GPC), an inflammatory reaction where bumps form on the inner eyelid. GPC is often linked to chronic irritation from contact lenses and protein deposits, making lens wear uncomfortable and potentially leading to lens intolerance.
Extended Wear Lenses: An Exception
Some contact lenses are specifically designed for extended or continuous wear, allowing them to be worn overnight. These lenses have higher oxygen permeability than traditional lenses, which helps the cornea receive more oxygen even with closed eyelids. Extended wear lenses may be approved for continuous wear for up to six nights and seven days, with some types approved for up to 30 days.
Even extended wear lenses carry a higher risk of complications compared to daily wear lenses. The risk of infection, including microbial keratitis, is still present. Therefore, these lenses should only be used under the guidance of an eye care professional, who can assess individual suitability and monitor eye health closely.
Accidental Overnight Wear: What to Do
If you accidentally fall asleep with your contact lenses in, avoid immediately attempting to remove them, especially if they feel dry or stuck. The lenses may have dehydrated and adhered to the cornea, and forceful removal could cause damage. Instead, gently massage your closed eyelids to encourage natural tear production or apply a few drops of saline solution or rewetting drops to rehydrate your eyes and the lenses.
Once your eyes feel lubricated and the lenses move freely, carefully remove them. Discard these lenses, as they may have accumulated debris and bacteria. After removal, monitor your eyes for any signs of discomfort, redness, pain, blurry vision, or discharge. If any symptoms persist for more than a day, contact your eye care professional immediately, as this could indicate an infection or other complication.