Written and maintained by CASRAI Editorial Board
Last updated
General information from public health sources, not medical advice. Contact lens wearers with eye pain, redness or vision changes should contact an eye care professional.
Short answer
The US Centers for Disease Control and Prevention (CDC) says to replace a contact lens case at least once every three months. The interval is only part of the picture: studies of real wearers show that cases become contaminated within weeks and that many people go well past the advised interval, so the CDC’s daily case-care statements matter as much as the date on the calendar.
Definition and scope
A contact lens case is the small container that holds lenses and lens solution while the lenses are not being worn. “Case replacement” means discarding the case and starting with a new one, as distinct from cleaning the case between uses. This page covers the replacement interval and the evidence around it. It does not cover how often the lenses themselves are replaced, which depends on the lens type; see the daily vs monthly contact lenses comparison for that. It gives no product recommendations, prices or brand comparisons.
What the CDC says about case replacement and care
The CDC’s page Preventing Eye Infections When Wearing Contacts (checked 2026-10-30) states: “Replace case at least once every three months.” Its travel tips repeat the same interval: “Replace your contact lens case every three months.” The page also advises storing the case upside down with caps off after each use.
The CDC’s page About Cleaning, Disinfecting, and Storing Contact Lenses (checked 2026-10-30) covers the care between replacements. It says to rub and rinse the storage case with fresh solution and to avoid any use of water, to empty excess solution and dry the case with a fresh, clean tissue, and not to mix fresh solution with old or used solution in the case, because that reduces disinfection effectiveness. That page does not itself give a replacement interval; the three-month figure comes from the prevention page.
Advice versus behaviour: what the studies measured
The table sets the CDC advice beside what peer-reviewed studies measured in wearers. Each row is traced to the source named in it. The studies used different samples and countries, so the rows are not a single population and the percentages should not be added together or compared across rows.
| CDC advice | What was measured | Source |
|---|---|---|
| Replace the case at least every three months | 26.4% of 299 nondaily wearers surveyed had not replaced the case within 6 months of acquiring it | Cardona, Alonso and Yela, Optometry and Vision Science 2022;99(5):449-454 (PubMed 35165235) |
| Rub and rinse the case with fresh solution | 19.1% of the same 299 wearers never cleaned their cases | Cardona et al. 2022 |
| Avoid any use of water with the case | 68.6% of the 299 wearers exposed the case to tap water; in a separate study of 165 daily soft lens wearers, 17.5% used tap water to rinse cases | Cardona et al. 2022; Arshad et al., Optometry and Vision Science 2021;98(9):1002-1010 (PubMed 34570032) |
| Keep the case clean to limit bacterial buildup | In a randomized trial of 38 participants wearing daily for 2 weeks with four care solutions, more than 80% of storage cases were contaminated; contamination ranged from 0 to 6.4 log CFU per well and was not modulated by lens material | Dantam et al., Optometry and Vision Science 2016;93(8):925-932 (PubMed 27254809) |
Why the interval alone is not the control
Dantam and colleagues found contamination in most cases after only two weeks of daily wear, long before a three-month replacement date. A fresh case therefore does not stay clean on its own; the daily statements from the CDC (rinse with fresh solution, no water, dry, caps off, no topping off) apply from the first day. Water exposure adds to this: Arshad and colleagues reported that showering with lenses was associated with higher case bioburden (P=.001) and that wet hands roughly doubled the odds of higher endotoxin (odds ratio 2.41, 95% CI 1.19-4.86).
Cardona and colleagues also noted that wearers’ awareness of the risk was high while compliance was poor, so the gap lies in routine, not in knowing that cases matter.
Where it matters for clinics and supply decisions
For clinic and eye-care staff, the sourced point is about patient education. Wu, Carnt, Willcox and Stapleton (Eye and Contact Lens 2010;36(2):68-72, PubMed 20090543) compared case-hygiene advice in five multipurpose solution inserts, the FDA website and 77 optometrists in New South Wales, Australia, and concluded that case cleaning instructions were inconsistent, with limited recommendations on drying positions, rinsing and rubbing. That study dates from 2010, so current labels may differ, which is one reason to anchor patient materials on the current CDC wording. For related clinic planning, see the optometry clinic supply checklist, the ophthalmology surgery center supply checklist and the background guide what is ophthalmology.
Common misunderstandings
“The case lasts as long as the lenses”
The CDC states the case interval (at least every three months) separately from any lens replacement schedule.
“Rinsing the case with water is fine”
The CDC advises avoiding any use of water with the case and rinsing with fresh solution. Both surveys above found substantial tap-water exposure.
“Topping off old solution saves a step”
The CDC says not to mix fresh solution with old or used solution in the case, because it reduces disinfection effectiveness.
“A new case is clean for months”
In the Dantam trial most cases were contaminated within two weeks of daily wear, so replacement does not replace daily care.
“Eye wash is the same as lens solution”
Eye wash and contact lens solution are separate products; see eye wash solution for what eye wash is.
FAQ
How often should I replace a contact lens case?
The CDC says at least once every three months (CDC, checked 2026-10-30). Follow the advice of your eye care professional and the instructions on your lens solution.
Can I rinse the case with water?
The CDC advises avoiding any use of water with the case and rinsing it with fresh solution. In a 2022 survey, 68.6% of 299 nondaily wearers reported exposing the case to tap water.
Does replacing the case mean I can skip cleaning it?
No. A trial of daily wear found more than 80% of storage cases contaminated after two weeks, so the CDC’s rinse, dry and caps-off statements apply to a new case as well.
Sources
- CDC, Preventing Eye Infections When Wearing Contacts, checked 2026-10-30.
- CDC, About Cleaning, Disinfecting, and Storing Contact Lenses, checked 2026-10-30.
- Dantam J et al. Optom Vis Sci 2016;93(8):925-932. PubMed 27254809, doi 10.1097/OPX.0000000000000886, checked 2026-10-30.
- Cardona G, Alonso S, Yela S. Optom Vis Sci 2022;99(5):449-454. PubMed 35165235, doi 10.1097/OPX.0000000000001881, checked 2026-10-30.
- Arshad M et al. Optom Vis Sci 2021;98(9):1002-1010. PubMed 34570032, doi 10.1097/OPX.0000000000001772, checked 2026-10-30.
- Wu Y, Carnt N, Willcox M, Stapleton F. Eye Contact Lens 2010;36(2):68-72. PubMed 20090543, doi 10.1097/ICL.0b013e3181cf8aff, checked 2026-10-30.
