Cleaning your contact lens case takes less than a minute, but most people skip steps or do it wrong. A properly cleaned case gets emptied, rubbed out with fresh solution, and air-dried face down every single day. Skipping any of those steps lets bacteria build protective layers on the plastic that even disinfecting solution can’t penetrate.
The Daily Cleaning Routine
Every morning after you put your lenses in, empty all the old solution out of the case. Never top off yesterday’s solution with fresh liquid. Pour it out completely.
Next, rub the inside of each well with clean fingers and fresh multipurpose solution. This physical rubbing is the most important part. Bacteria stick to the plastic surface and form a thin, resilient film called a biofilm. Research has shown that this biofilm resists the normal disinfection cycle, meaning soaking alone won’t kill everything. Rubbing physically breaks up that film so the solution can actually do its job. Rinse both wells and the caps with fresh solution after rubbing.
Then leave the case open to air dry, face down, on a clean tissue. A study comparing drying positions found that cases dried face up were contaminated 71% of the time, while cases dried face down were contaminated only 12% of the time. Gravity pulls residual moisture out of the wells instead of letting it pool at the bottom where bacteria thrive. Place the caps face down alongside the case so they dry completely too.
What to Use (and What Never to Use)
Always rinse and rub your case with the same multipurpose solution you use for your lenses, or with sterile saline. Never use tap water. Tap water commonly contains Acanthamoeba, a microorganism that can cause a serious, painful eye infection called Acanthamoeba keratitis. The EPA specifically warns against letting tap water come into contact with anything that touches your lenses. That includes rinsing the case under the faucet, which many people do out of habit.
If you use a hydrogen peroxide system, your case is different from a standard one. It contains a neutralizing disc that converts the peroxide into saline over several hours. These cases should only be rinsed with sterile saline or fresh peroxide solution, never multipurpose solution. Follow the replacement schedule that comes with your specific system, since the neutralizing disc wears out over time.
Replace the Case Every Three Months
The American Academy of Ophthalmology recommends replacing your contact lens case at least every three months, or immediately if it’s cracked or damaged. Even with perfect daily cleaning, biofilm builds up in microscopic scratches in the plastic over time. Research has found that manufacturer recommendations for case hygiene may be inadequate to fully remove microbial biofilm from lens storage cases. A fresh case resets the clock.
Most multipurpose solution bottles come with a new case in the box. If yours doesn’t, cases cost a dollar or two at any pharmacy. There’s no reason to stretch one past three months.
Can You Boil a Contact Lens Case?
Boiling does work as a disinfection method. Research published in the Journal of the American Optometric Association found that boiling a contaminated case for 20 minutes eliminated Acanthamoeba cysts completely, even in the presence of organic debris. However, some plastic cases can’t withstand boiling for more than five minutes before warping or cracking. If the case deforms, it creates new hiding spots for bacteria and defeats the purpose.
Boiling can be a useful backup if you suspect contamination, but it’s not a substitute for daily cleaning and regular replacement. If you’re worried enough to boil your case, you’re better off just replacing it with a new one.
Traveling With Your Case
The TSA classifies contact lens solution as a medically necessary liquid, which means you can bring more than the standard 3.4-ounce limit in your carry-on bag. You do need to declare it to security officers at the checkpoint. That said, the TSA recommends placing bottles larger than 3.4 ounces in checked baggage to speed up screening.
The bigger risk while traveling is cutting corners with your routine. Hotel sinks, bottled water, and airport bathroom taps are all forms of non-sterile water that should never touch your case. Bring enough solution for your entire trip, pack a spare case, and stick to the same rub, rinse, and air-dry steps you use at home. If you run out of solution and can’t get more right away, wearing your glasses for a day is far safer than improvising with water.
Common Mistakes That Cause Problems
- Topping off old solution. Adding fresh solution to yesterday’s leftover liquid dilutes the disinfectant concentration below what’s needed to kill bacteria. Empty the case fully every time.
- Storing the case in the bathroom. Humidity from showers keeps the case damp and promotes bacterial growth. A bedroom dresser or nightstand is a better spot for drying.
- Skipping the rubbing step. Even solutions labeled “no-rub” work better with a quick rub. The mechanical action is what disrupts biofilm that solution alone can’t dissolve.
- Closing the case while still wet. Sealing in moisture creates exactly the warm, damp environment bacteria prefer. Leave both wells and caps open until completely dry.