Contact Lenses Day Night

Day and night contact lenses are approved for continuous wear including during sleep, unlike standard lenses that require nightly removal. They are made from silicone hydrogel material with high oxygen transmissibility, allowing the cornea to receive enough oxygen even when the eyes are closed.

The key difference between extended and continuous wear is the approved duration. Extended wear covers up to six nights and seven days. Continuous wear covers up to 30 nights of uninterrupted use before removal and replacement. Not every wearer qualifies for the maximum approved duration. Eye doctors evaluate tear film quality, corneal health, lens fit, and lifestyle before recommending a schedule. The right wear period is determined clinically, not by the lens approval alone.

The cornea has no blood vessels and relies on ambient oxygen during waking hours. When the eyes close, it switches to dissolved oxygen carried through the tear film behind the lens. Standard soft lens materials restrict this flow significantly, raising the risk of corneal hypoxia during sleep.

Silicone hydrogel addresses this by transmitting substantially more oxygen than standard hydrogel. Air Optix Night & Day Aqua, made from lotrafilcon A, carries a Dk/t of 175, the highest oxygen transmissibility of any soft contact lens material on the market. This reduces but does not fully eliminate overnight wear risks.

Sleeping in lenses not approved for overnight wear is clinically unsafe. A CDC study found it increases the risk of serious eye infection by six to eight times compared to proper daily wear, with several documented cases resulting in permanent eye damage.

Even with approved lenses, the risk of microbial keratitis, a potentially vision-threatening corneal infection, remains higher than with daily wear. The warm, moist environment under a closed eyelid creates conditions where bacteria multiply rapidly. Regular monitoring from an eye care professional is required throughout any continuous wear period.

Day and night lenses are typically prescribed for wearers whose occupation or lifestyle makes daily removal impractical. This includes shift workers, first responders, military personnel, and frequent travelers, as well as wearers with dexterity limitations that make daily handling difficult. Candidacy is determined by an eye doctor after a full evaluation.

Even when a lens carries continuous wear approval, individual eye health determines whether overnight use is safe. Eye doctors advise against day and night lenses for wearers with any of the following:

• A history of corneal infection, ulcers, or significant scarring
• Dry eye syndrome or poor tear film quality
• Blepharitis or chronic eyelid inflammation
• Conditions that suppress immune response
• A smoking history, as smokers have a clinically higher incidence of adverse reactions with contact lens wear
• Prior non-compliance with lens care or replacement schedules

Remove the lenses as soon as you wake up. Do not pull out a dry lens. Use lubricating eye drops first to rehydrate before removal, then avoid wearing lenses for the rest of the day. If redness, pain, light sensitivity, blurred vision, or discharge persists after removal, contact your eye doctor before resuming wear. These symptoms can indicate corneal abrasion, hypoxia, or early infection.

Remove day and night lenses immediately if any of the following occur, even within an approved wear period:

• Persistent redness that does not improve after blinking or lubricating drops
• Sharp pain, burning, or stinging in one or both eyes
• Blurry or hazy vision that appears suddenly
• Unusual light sensitivity or discomfort in bright environments
• Excessive tearing or discharge from the eye
• A feeling of something caught under the lens that does not resolve

Do not reinsert the lenses if symptoms continue. Contact your eye doctor before resuming wear.

Contact Lenses: What to Know Before You Buy. U.S. Food and Drug Administration. https://www.fda.gov/consumers/consumer-updates/contact-lenses-what-know-you-buy. Accessed June 23, 2026.

Corneal Infections Associated with Sleeping in Contact Lenses. Centers for Disease Control and Prevention. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6095652/. Published August 17, 2018. Accessed June 23, 2026.

Extended Wear Contact Lenses. CooperVision. https://coopervision.com/about-contacts/extended-wear-contact-lenses. Accessed June 23, 2026.

Risks of Sleeping in Contact Lenses. Washington University Ophthalmology and Visual Sciences. https://ophthalmology.wustl.edu/risks-of-sleeping-in-contact-lenses-and-benefits-of-lasik/. Accessed June 23, 2026.

Healthy Vision and Contact Lenses. American Optometric Association. https://www.aoa.org/healthy-eyes/vision-and-vision-correction/healthy-vision-and-contact-lenses. Accessed June 23, 2026.