Daily vs Monthly Contact Lenses: Which Is Actually Better for You?

By Navid H., Licensed Optician  |  Charm Optical  |  5035 Ellerslie Road SW, Edmonton, AB T6X 1X2  |  March 2026  |  10 min read

If you wear contact lenses or are thinking about starting, this is one of the first questions you face: daily or monthly? Both correct your vision. Both sit on your eye. But they are meaningfully different in how they are made, how they perform over time, how they affect eye health, and what they cost per year.

At Charm Optical on Ellerslie Road we fit contact lenses for patients from Windermere, Heritage Valley, Rutherford, Summerside, Chappelle, Ellerslie, and all across south Edmonton. This question comes up at nearly every contact lens appointment. The honest answer: neither is universally better. The right choice depends on your lifestyle, eye health, prescription, and hygiene discipline.

Source: A sixteen year survey of Canadian contact lens prescribing — PubMed, University of Waterloo Centre for Ocular Research and Education (CORE)

Both are soft contact lenses that correct your vision by altering how light focuses on the retina. But materials, thickness, and design philosophy differ because they are engineered for different lifespans.

Daily Disposable Lenses

Designed for one waking day of wear, discarded at the end of that day. No cleaning, no storage, no reinsertion. Each morning is a fresh, sterile pair. Daily lenses are thinner and optimized for single-use comfort. A 2024 international prescribing survey in Contact Lens and Anterior Eye (ScienceDirect) — covering 260,144 lens fits across 20 countries — found silicone hydrogel now represents 73.7% of all daily wear soft lens fits, up from just 2.8% in 2000.

Monthly Replacement Lenses

Designed to be worn daily, removed each night, cleaned with solution, stored in a case, and replaced after 30 days of wear. Thicker and more durable than dailies — built for repeated handling over a full month. The 25-year silicone hydrogel review in PMC (2025) confirms silicone hydrogel monthly lenses have "largely eliminated hypoxia as a complication" when worn correctly during daytime only.

Sources: ScienceDirect — International trends in silicone hydrogel prescribing (2024) | PMC — Twenty-five years of silicone hydrogel soft contact lenses (2025)

Your cornea has no blood vessels. It gets oxygen directly from the air through your tear film. A contact lens acts as a partial barrier to that supply. A PMC review of contact lens complications (2022) confirms: "the avascular cornea derives oxygen directly through the tear film. Overwear of contact lenses disrupts this process." Before silicone hydrogel existed, chronic oxygen deprivation from lenses caused irreversible corneal changes. Modern silicone hydrogel lenses achieve Dk/t values between 55-150 units, making both daily and monthly silicone hydrogel lenses adequate for daytime corneal oxygenation.

Conventional wisdom says dailies are always safer because you never store them. The clinical research is more nuanced. A 2025 study in Acta Ophthalmologica (PMC) tracked all patients hospitalized for severe contact lens keratitis over three years at Oslo University Hospital:

Sources: PMC — Incidence risk factors severe contact lens microbial keratitis (2025) | PMC — Contact lens associated microbial keratitis (2023) | PMC — Contact lens-associated keratitis University of Freiburg (2023)

The bottom line: it is overnight wear — not daily vs monthly — that primarily drives infection risk. A PMC keratitis review states daily disposables "do not eliminate the risk of MK, however, there may be a lower risk of vision loss" compared with planned replacement lenses.

The biggest practical risk with monthly lenses is that most people don't replace them on time. A PubMed compliance study from University of Waterloo CORE found:

Source: PubMed — Compliance with contact lens replacement in Canada and the United States — University of Waterloo CORE

A monthly lens worn 45 days instead of 30 accumulates significantly more protein and lipid deposits, reducing oxygen permeability over time and directly increasing infection risk per the PMC risk factor review. The theoretical risk difference between a properly worn monthly and a daily is small. The real-world difference — accounting for actual human compliance — is larger.

Daily Disposables Are Usually Better If...

•       You have eye allergies  — fresh lenses daily eliminate allergen and pollen buildup on the lens surface

•       You are a part-time or occasional wearer  — for sports or social use, daily lenses let you use exactly what you need

•       You have a history of contact lens complications  — eliminating the storage system removes accumulated deposits as a variable

•       Convenience is the priority  — no solution, no case, no cleaning. Insert in the morning, discard at night

•       You are a new contact lens wearer  — reduces hygiene variables while you build confidence with lens handling

Monthly Replacement Lenses Are Usually Better If...

•       You wear contacts full-time every day  — monthly lenses are significantly more cost-effective for daily committed wearers

•       You have a complex prescription  — Biofinity Toric, Air Optix HydraGlyde for Astigmatism, and Bausch+Lomb ULTRA for Astigmatism offer wider monthly toric parameter ranges

•       You are reliably disciplined about hygiene  — remove, clean, and store every night; replace exactly on schedule; replace the case every 3 months

•       Cost is the primary concern  — monthly lenses cost meaningfully less per year for daily wearers who comply properly

Astigmatism — Toric Lenses

Both daily and monthly toric options available at Charm Optical: Acuvue Oasys 1-Day for Astigmatism, Dailies AquaComfort Plus Toric, MyDay Toric, Biofinity Toric, and Bausch+Lomb ULTRA for Astigmatism. Higher cylinder prescriptions often have better monthly parameter availability.

Dry Eyes — Edmonton's Climate

Edmonton is one of the driest cities in Canada. Protein and lipid deposits on a monthly lens reduce moisture properties over 30 days. Daily lenses always start fresh. Dailies Total1 and Acuvue Oasys 1-Day use water-gradient silicone hydrogel technology engineered for dry conditions. For monthly wearers with dry eyes, TOTAL30 uses similar water-gradient technology.

Presbyopia Over 40

Both daily and monthly multifocal options exist. Biofinity and TOTAL30 are strong monthly multifocal options. Multifocal fitting requires a specialized in-store appointment — not a simple prescription swap.

Active Lifestyles

Daily disposables are practical for sports — discard after activity, no case or solution needed on the go. Never swim in contact lenses regardless of type. Fresh and pool water harbor Acanthamoeba and other organisms causing severe corneal infections. Use prescription goggles for water activities.

The PMC keratitis review found that in a survey of nearly 1,000 contact lens wearers, only 1% reported following all hygiene directions. Poor hygiene — not lens type — is the leading driver of contact lens complications.

•       Wash and fully dry hands before every insertion and removal

•       Never sleep in lenses not approved for overnight wear  — the single most important rule

•       Never rinse, store, or top up lenses with tap water  — Edmonton tap water can harbor Acanthamoeba

•       Never swim or shower in contact lenses

•       Replace lens case every 3 months  — cases are the most contaminated item in a contact lens kit

•       Never extend the replacement schedule  — a 30-day lens worn for 45 days carries elevated infection risk

We help patients choose and fit contact lenses every week at Charm Optical, 5035 Ellerslie Road SW, Edmonton, AB T6X 1X2. We see patients from Ellerslie, Windermere, Heritage Valley, Summerside, Rutherford, Chappelle, Cavanagh, Ambleside, Allard, Callaghan, Blackmud Creek, The Meadows, Walker, Twin Brooks, Mill Woods, Beaumont, Leduc, Nisku, and Sherwood Park. A proper fitting includes corneal curvature measurement, eye health evaluation, lens brand and type selection, and a trial fitting. We carry Acuvue, Dailies, CooperVision, Bausch + Lomb, and Alcon in-stock with direct billing for all major Alberta insurance providers.

Can I sleep in my contact lenses occasionally?

Strongly discouraged. The 2025 PubMed study found overnight wearers had 2.52 per 10,000 severe infections annually vs 0.52 for daytime daily disposable users. If you fall asleep accidentally, remove lenses immediately upon waking, do not reinsert, and monitor for redness or irritation. If symptoms persist, call us at (780) 490-0090.

Do daily lenses have less infection risk than monthly?

Research is nuanced. Dailies are associated with less severe vision loss when infections occur. But overall keratitis incidence in properly worn daytime monthly lenses is not dramatically different from dailies. What makes dailies safer in practice is eliminating the lens case and cleaning solution — common contamination sources — and removing the temptation to overwear.

How do I know if my contact lens blister pack is expired?

Every blister pack has an expiry date printed on it. Never open or use a lens past that date — the sterility of the saline solution and the lens material cannot be guaranteed after expiry. Expired lenses should be discarded without use.

What should I do if my eye becomes red or painful with contacts in?

Remove the lens immediately. Do not reinsert. If symptoms persist after removal, or you have pain, light sensitivity, or vision changes, seek same-day assessment — contact lens corneal infections progress rapidly. Call us at (780) 490-0090 or visit 5035 Ellerslie Road SW, Edmonton, AB T6X 1X2.

How often do I need a contact lens exam?

The Canadian Association of Optometrists recommends annual eye exams for all contact lens wearers — not just a prescription check, but assessment of corneal health under lens wear. AHCIP covers annual exams for children under 19. Adults 19-64 should check employer benefits.

• PMC — Incidence, risk factors, severe contact lens microbial keratitis (2025)

• PMC — Contact lens associated microbial keratitis: practical considerations (2023)

• PMC — A Review of Contact Lens-Related Risk Factors and Complications (2022)

• PMC — Contact Lens-Associated Keratitis — University of Freiburg (2023)

• PMC — Contact Lens Use Advice: Risks and Outcomes (2023)

• PMC — Twenty-five years of silicone hydrogel soft contact lenses (2025)

• ScienceDirect — International trends in silicone hydrogel contact lens prescribing 2000-2023 (2024)

• PubMed — Sixteen year survey of Canadian contact lens prescribing — University of Waterloo CORE

• PubMed — Compliance with contact lens replacement in Canada and the United States — University of Waterloo CORE

• Canadian Association of Optometrists — Eye health guidance

• Charm Optical — All Contact Lenses

• Charm Optical — Acuvue

• Charm Optical — Dailies

• Charm Optical — CooperVision

• Charm Optical — Bausch + Lomb

• Charm Optical — Alcon

• Charm Optical — Insurance Providers

• Charm Optical — Book an Eye Exam