Sauna culture is growing fast in the UK, with hundreds of new venues opening in the last two years. For contact lens wearers, especially those who wear coloured lenses, the question is a practical one: do the lenses come out before you go in? This guide explains the risks clearly, covers why coloured lenses carry extra considerations, and tells you exactly what to do if you have already made the mistake once.
No. Contact lenses in a sauna are not safe. The intense heat causes lenses to dehydrate rapidly, which can tighten them against the cornea and increase infection risk. Coloured contact lenses carry additional risk because the pigment layer further restricts oxygen permeability under heat stress. Remove your lenses before entering any sauna, including infrared models.
Why Saunas Are a Problem for Contact Lens Wearers
The UK sauna boom has brought this question to the forefront. According to the British Sauna Society, the number of public sauna sites in the UK grew from 45 in 2023 to over 147 in 2024, with the figure expected to exceed 200 by the end of 2025. That is a very large number of new environments where contact lens wearers need clear, practical guidance. For a broader understanding of contact lens safety across different situations, our guide on contact lens safety covers the key principles.
What Heat Does to Your Lenses
Soft contact lenses, including all coloured lenses, are made from hydrogel materials containing 40 to 55 per cent water. In a standard Finnish or traditional sauna, temperatures reach 80 to 100 degrees Celsius. At those temperatures, the water content of your lens evaporates significantly faster than the tear film beneath it can replenish. The lens shrinks slightly as it dries, which causes it to tighten against the surface of the cornea.
A lens that has dried and contracted on the eye is uncomfortable to wear, difficult to remove safely, and capable of causing corneal abrasion if you attempt to remove it without rehydrating first. Research published by Chan et al. in 2021 demonstrated measurable decreases in lens water content at temperatures as low as 35 degrees Celsius, which is far below sauna conditions.
The Infection Risk: Acanthamoeba and Bacteria
The warm, humid environment inside a sauna, including the steam released by water on hot stones and the perspiration that reaches the eyes, creates conditions that favour the growth of micro-organisms. Acanthamoeba is a microscopic organism found in water sources including heated environments such as saunas and hot tubs. It is able to survive in the space between a contact lens and the cornea, where it can cause Acanthamoeba keratitis, a serious and potentially sight-threatening infection. Studies show that over 90 per cent of Acanthamoeba keratitis cases occur in contact lens wearers. The College of Optometrists in the UK consistently advises against wearing contact lenses in any environment where water or steam contacts the eye surface.
This article is for informational purposes only and does not constitute clinical eye care advice. If you experience any eye pain, redness, or changes in vision after wearing contact lenses in a sauna or steam room, contact your optician promptly or call NHS 111.
Finnish Sauna, Infrared & Steam Room: Are Any Safer?
Not all sauna environments are identical, and it is worth understanding how each type affects contact lenses differently. The table below compares the three most common environments in UK venues.
|
Type |
Temperature |
Humidity |
Risk for Lenses |
Recommendation |
|---|---|---|---|---|
|
Finnish / Traditional |
80–100°C |
Low–medium |
High — rapid dehydration, lens tightens on cornea |
Remove before entering |
|
Infrared |
50–60°C |
Very low |
Medium–high — IR heats water in lens directly |
Remove before entering |
|
Steam Room |
40–50°C |
Very high |
High — bacteria + lens warping risk |
Remove before entering |
While infrared saunas operate at lower temperatures than traditional Finnish saunas, they present a specific concern for lens wearers that is often overlooked. Infrared light is absorbed by water, which means it heats the water content within soft contact lenses directly, rather than simply warming the surrounding air.
This means the lens itself may reach a higher effective temperature than the ambient sauna temperature suggests. For steam rooms, the combination of very high humidity and warm temperatures creates an environment where bacteria and fungi thrive, and where the lens surface is more prone to bacterial contamination than in dry heat. In all three cases, the recommendation from eye care professionals remains the same: remove your lenses before entering.
Why Coloured Contact Lenses Carry Extra Risk in a Sauna
This is an important distinction that most general guidance on contact lenses in saunas does not address. Coloured contact lenses have a pigment layer encapsulated within the lens material. This layer is safe during normal wear and does not come into contact with the eye surface. However, the pigment layer adds a structural barrier within the lens that reduces oxygen transmissibility compared with a clear lens of the same base material. To understand more about how different lens materials affect oxygen flow, our guide to contact lens materials covers this in detail.
When heat stress is added to this equation, the result is a compounded effect. A coloured lens in a sauna environment faces both the dehydration-driven reduction in oxygen permeability and the inherent structural limitation of the pigment layer. The cornea, which has no blood supply and depends entirely on atmospheric oxygen dissolved through the tear film, is placed under greater stress than it would be with a clear lens in the same environment. This makes it even more important for coloured lens wearers to remove their lenses before any sauna session, regardless of session duration.
All lenses in the Bella range, including the Elite, Natural, Contour, and Daily collections, are standard soft hydrogel coloured lenses. None are designed or approved for use in high-heat environments. For sauna visits, the lens goes out, every time.
For comfortable everyday coloured lens wear within recommended hours, Bella Daily lenses offer a convenient single-use option: Bella Daily Contact Lenses.
What to Do If You Accidentally Wore Your Lenses in a Sauna
It happens. You forgot to take them out, or your session was brief and you assumed it would be fine. The right response depends on how long you were inside and how your eyes feel afterwards.
Step 1: Do not attempt to remove the lenses immediately if your eyes feel dry. A dried, contracted lens pulled off the cornea can cause corneal abrasion. Apply preservative-free rewetting drops approved for use with contact lenses and blink gently.
Step 2: Wait two to three minutes. Once the drops have rehydrated the lens and it moves freely on the eye, remove it using your normal technique.
Step 3: Discard daily disposables immediately. Never reinsert a daily lens that has been worn in a sauna. Monthly or bi-weekly coloured lenses should be cleaned and disinfected with fresh solution before any further use.
Step 4: Rest your eyes. Wear glasses for several hours to allow the cornea to recover its normal oxygen supply and tear film balance.
Step 5: Monitor for 48 hours. Watch for redness that does not resolve, worsening discomfort, light sensitivity, discharge, or any visual changes. These may indicate a developing corneal issue.
If you experience pain, increasing redness, or any change in vision after wearing contact lenses in a sauna, seek advice from your optician promptly. Do not reinsert lenses until your eyes have been assessed.
Before and After Sauna: A Routine for Contact Lens Wearers
The most effective strategy is building removal into your pre-sauna routine so it becomes automatic rather than an afterthought. For guidance on how to store and care for your lenses properly between sessions, our guide to choosing the right contact lens solution covers everything you need to know.
Before the sauna. Remove lenses before you enter the changing room, not when you are already at the sauna door. Place them in a clean lens case with fresh multipurpose solution. Store the case in your locker or bag, away from any warm areas near the sauna itself. Prolonged heat exposure near the sauna environment can also degrade the solution in your case.
After the sauna. Allow at least 20 to 30 minutes for your eyes to return to their normal temperature and humidity balance before reinserting lenses. If your eyes feel dry or irritated after the session, use preservative-free rewetting drops and wait longer before putting lenses back in.
For coloured lens wearers specifically. Consider making a habit of removing coloured lenses whenever you visit a spa, gym, or wellness venue, even if you do not plan to use the sauna. If plans change and you end up in the steam room or heat area, you are already protected.
What to Use in a Sauna If You Need to See Clearly
Most people do not need sharp vision in a sauna. The environment is small, the light is low, and sessions are short. For the vast majority of sauna users, going in without any visual correction is entirely manageable. If you need to navigate an unfamiliar venue or larger spa complex, consider positioning yourself near the door before removing your lenses, or asking a companion to guide you. If you have a significant prescription and visibility is a genuine concern, lightweight prescription glasses left nearby outside the sauna give you clear vision the moment you step out, without any of the risks associated with wearing contact lenses inside.
Final Thoughts
Contact lenses in a sauna is one of those situations where the question seems minor but the potential consequences are not. For coloured lens wearers, the answer is particularly clear: the pigment layer adds an additional oxygen restriction that makes heat exposure more problematic than it would be with a clear lens. Build lens removal into your pre-sauna routine, keep a lens case in your bag whenever you visit a spa or wellness venue, and your eyes will thank you for a straightforward habit that takes under a minute to establish.
See more: Are Contact Lenses Safe? What UK Wearers Should Know
