Monthly contact lenses are soft lenses designed to be worn for up to 30 days before being replaced with a fresh pair. You wear them during the day, remove them each night, clean and store them in disinfecting solution, and put the same pair back in the next morning. At the end of the month, you throw them away and open a new pair. They’re one of the most popular replacement schedules, sitting between daily disposables (one use, then tossed) and older conventional lenses that lasted six months to a year.
How Monthly Lenses Differ From Dailies
The core difference is reuse. Daily disposable lenses come in individual blister packs, one pair per day, no cleaning required. Monthly lenses come in fewer packages (typically a three- or six-month supply in a single box) but require nightly cleaning and a storage case. This changes both cost and routine in meaningful ways.
Annually, monthly lenses cost roughly $240 for the lenses themselves, plus $150 to $200 for cleaning solutions and replacement cases. That puts the total around $390 to $440 per year. Daily disposables, by contrast, run about $720 or more per year depending on brand and prescription, but you skip the cleaning supplies entirely. If you wear contacts every day, monthlies are significantly cheaper. If you only wear contacts a few times a week, dailies can be more economical since you’re not opening a monthly pair just to use it occasionally.
Materials and Oxygen Flow
Most modern monthly lenses are made from silicone hydrogel, a material that allows five to ten times more oxygen to reach the cornea compared to older hydrogel materials. Oxygen matters because the cornea has no blood vessels. It gets oxygen directly from the air, and a contact lens sits right on top of it, acting as a partial barrier. Silicone hydrogel keeps the cornea healthier during long wearing hours, which is especially important for a lens you’re reusing for 30 days.
Some monthly lenses also feature surface treatments designed to retain moisture throughout the day. These coatings create a water-rich outer layer that resists protein and lipid buildup from your tear film, helping the lens feel more comfortable in the final weeks of its life cycle when deposits would otherwise accumulate.
Who They Work For
Monthly lenses are available in a wide range of prescriptions. Standard spherical lenses correct nearsightedness and farsightedness. Toric versions correct astigmatism, with cylinder powers and multiple axis options to match the specific shape of your cornea. Multifocal monthlies handle presbyopia (the age-related loss of near-focus that typically starts in your 40s), and some newer designs combine multifocal and toric correction in a single lens for people who need both.
Prescription parameters for monthly lenses are generally broader than for dailies. If you have a strong prescription or significant astigmatism, you may find that monthly lenses offer options that simply don’t exist in a daily disposable format.
The Cleaning Routine
Caring for monthly lenses is non-negotiable. Skipping steps or cutting corners is the fastest way to develop an eye infection. The CDC recommends a specific routine every time you remove your lenses.
The two main solution types are multipurpose solution (cleans, rinses, disinfects, and stores in one product) and hydrogen peroxide-based systems (which use a special case to neutralize the peroxide into saline over several hours). Saline alone does not disinfect, so it should never be your only solution.
Each night, you should:
- Rub and rinse each lens with fresh solution, even if your solution says “no rub” on the label
- Fill the case with fresh solution every time, never topping off old solution with new
- Clean the case itself by rubbing and rinsing it with solution (not water), then drying it with a clean tissue and storing it upside down with the caps off
Replace your lens case at least every three months, or whenever your solution bottle comes with a new one. Biofilm, a thin layer of bacteria, builds up inside cases over time and survives even in disinfecting solution once it’s established.
Infection Risk
Monthly lenses carry infection risk primarily because of the reuse cycle. Every time you handle, store, and reinsert a lens, there’s an opportunity for bacteria to reach your eye. That said, the risk is often overstated in comparison to dailies. A study published by the American Academy of Ophthalmology found that daily disposable wearers actually had a 1.5 times greater risk of microbial keratitis (a serious corneal infection) than people using one- to four-week planned replacement lenses. The likely explanation: daily wearers may become complacent about hand hygiene because they assume the fresh lens protects them.
The real danger multiplier is sleeping in your lenses. Overnight wear of any lens type increases the risk of microbial keratitis fivefold. While certain monthly lenses are FDA-approved for extended (overnight) wear for up to 30 consecutive nights, most eye care professionals recommend removing lenses nightly regardless of approval status.
Extended Wear vs. Daily Wear
Not all monthly lenses are interchangeable. Some are approved only for daily wear, meaning you must remove them every night. Others carry FDA approval for continuous wear, letting you sleep in them for a set number of nights. The distinction depends on the lens material’s oxygen transmission rate.
If you want the option of occasionally sleeping in your lenses, you need a lens specifically approved for that purpose and a prescription that reflects extended wear. Sleeping in a daily-wear-only monthly lens, even once, raises your infection risk substantially because the material doesn’t transmit enough oxygen to keep the cornea healthy while your eyes are closed.
Environmental Footprint
Monthly lenses produce less packaging waste than dailies simply because you’re opening 12 blister packs per year instead of 730. However, the total plastic footprint is closer than you might expect. Daily disposables generate roughly 1 kg of plastic waste annually from lenses and packaging. Monthly lenses plus their solution bottles and replacement cases produce about 0.87 kg. The difference exists, but it’s modest. If environmental impact is a priority, the bigger factor is disposal method: contact lenses of any type should go in the trash, not down the drain, where they contribute to microplastic pollution in waterways.
Getting the Most From a Monthly Pair
Comfort and vision quality tend to decline in the last week of a monthly lens’s life. Protein and lipid deposits accumulate on the surface despite daily cleaning, and the material gradually dehydrates compared to its original state. A few practical habits help extend comfort throughout the full 30 days.
Track your replacement date. Write it on your calendar or set a phone reminder when you open a new pair. Many people lose track and wear lenses well past 30 days, which increases deposit buildup and infection risk. If a lens tears, develops a nick at the edge, or feels persistently uncomfortable before the month is up, replace it early. The 30-day window is a maximum, not a target to stretch.
Keep rewetting drops on hand for the later weeks of the cycle. Use only drops labeled as safe for contact lenses. And if you’re switching between glasses and contacts on different days, your monthly lenses still expire 30 days after opening, not after 30 days of actual wear. Once the blister pack is open, the countdown begins regardless of how often you use them.