The question of whether contact lenses (CLs) can be worn safely inside a sauna, including both traditional high-heat and modern infrared varieties, is common for vision-corrected individuals. Ophthalmologists and eye care professionals generally advise against wearing contact lenses in this high-heat, low-humidity environment. The combination of elevated temperature and rapid moisture loss compromises the physical integrity of the lens material and increases the risk of eye discomfort. The potential negative effects on eye health are significant enough to warrant caution.
Why High Heat Affects Contact Lenses
The primary issue within a sauna is the extreme temperature, which can range from 70°C to over 100°C in traditional saunas. This heat rapidly evaporates the tear film, the thin layer of fluid that lubricates the eye’s surface and keeps the lens comfortable. As the tear film evaporates, the contact lens begins to dehydrate, leading to immediate dryness, irritation, and a gritty sensation.
When a soft contact lens loses water content, its physical properties change. Studies show that increasing the temperature reduces the water content of all tested contact lenses, affecting the lens’s fit and oxygen transmissibility. This dehydration causes the lens to shrink, tighten, or potentially warp, altering its curvature. A poorly fitting lens can rub against the eye, leading to irritation or corneal abrasions.
A common misconception is that contact lenses will “melt” or fuse to the eye at typical sauna temperatures. This is inaccurate, as the melting point of the polymers used is far higher than the 100°C maximum found in a sauna. While they will not melt, the structural changes—namely shrinking and warping—are significant enough to pose a risk to the cornea and compromise vision. The physical changes in the lens material are a major concern, regardless of the debunked melting myth.
The Elevated Risk of Eye Infection
Beyond physical discomfort and lens warping, the sauna environment creates biological conditions that elevate the risk of serious eye infections. When the contact lens and the eye surface become excessively dry, the lens can move improperly, increasing the likelihood of creating tiny corneal abrasions. These micro-scratches on the corneal surface act as entry points for pathogens, making the eye more susceptible to infection.
The warm, moist environment of a sauna, particularly a steam sauna, is ideal for the growth and transfer of bacteria and fungi that adhere to the contact lens surface. The U.S. FDA warns against exposing contact lenses to water, including the humidity and steam found in saunas, because the lenses can absorb harmful organisms. This risk includes exposure to moisture-borne pathogens like Acanthamoeba, which can cause a severe, vision-threatening infection called Acanthamoeba keratitis.
This biological risk is compounded if a user attempts to re-wet a dried-out lens using tap water or a non-sterile solution. This practice introduces a high concentration of potential pathogens directly onto the eye. Compromising lens hygiene or the integrity of the corneal barrier in this hot, humid setting significantly increases the chances of developing a painful infection. The warmth and moisture essentially turn the contact lens into a breeding ground, trapping microbes against the eye surface.
Safe Vision Options While Using a Sauna
The safest practice for contact lens wearers is to remove the lenses entirely before entering the sauna, eliminating risks of dryness, warping, and infection. For individuals requiring vision correction to navigate the area, prescription eyeglasses are the best alternative. Standard plastic-framed glasses are generally safe to wear. However, metal frames should be avoided as they can absorb high heat and become hot enough to cause burns.
If removing the lenses is not an option, eye care professionals recommend using a fresh pair of daily disposable lenses and immediately discarding them upon exiting the sauna. This minimizes the risk of infection by ensuring a new, sterile lens is used and prevents re-wearing a lens exposed to high heat and potential pathogens. Using lubricating eye drops specifically formulated for contact lenses before and after the session can help maintain moisture and reduce dehydration.
For those who inadvertently wear their lenses into the sauna, the most important post-sauna care step is to remove and discard the lenses immediately. If the lenses are reusable, they must be thoroughly cleaned and soaked overnight in a disinfecting solution to minimize bacterial contamination. Should any irritation, prolonged redness, or blurred vision occur, an immediate consultation with an eye care professional is advised.