The short answer: Japan’s current standard MegRhythm steam eye mask provides warmth labelled at about 40°C for around 20 minutes. Look for the orange-red unscented 12-pack pictured below. Kao permits use with correctly worn contact lenses and says you may fall asleep wearing the mask. Those are separate permissions: the mask’s instructions do not make your contact lenses suitable for sleeping in.
I’m Irene, a Taiwanese pharmacist working in Japan. If you want a quiet break at your hotel but the eye-mask shelf looks confusing, start with the Japanese product name. Then check the two questions that matter at bedtime: contact lenses and falling asleep.
Find the current Japanese pack
Look for めぐりズム / MegRhythm, followed by 蒸気めぐるアイマスク 無香料. 無香料 means unscented; 12枚入 means 12 single-use masks. The barcode for this box is 4901301460547. Shoppers in Taiwan may know the brand as 美舒律; Chinese-language listings also use 花王蒸氣眼罩.
The August 2025 renewal changed the old Japanese name, 蒸気でホットアイマスク, and updated the material and fit. Older pictures remain online. Compare the full name, fragrance and count rather than judging solely by colour, and do not use a packaging difference alone to decide whether an item is genuine. Overseas packs and limited designs can look different; individual shop stock varies.
What does it do, and how does it feel?
This is a disposable warming item for a restful break, not a medical device. The thick, soft nonwoven mask has ear loops and warms when its pouch is opened. No plug, water or microwave is needed. Kao’s approximate temperature and comfort duration vary with the surroundings; a cold room can make the warmth feel less noticeable.
Unscented is a straightforward option if you do not want an added fragrance. Whether the warmth, thickness and fit feel pleasant is personal. If you have an eye condition or inflammation, wounds, swelling, eczema or another abnormality around your eyes, Kao says not to use it. Persistent discomfort is a reason to seek advice rather than keep warming the area.
My shopping tip: Decide whether you want a fragrance before choosing the box size. Unscented does not guarantee freedom from irritation. If you are unsure whether you will enjoy a warming mask, the standard unscented range also has a five-mask pack, so you need not start with several large boxes.
How to put it on
- Check your eyes and the surrounding skin first. Do not use it with the abnormalities above or if the mask is damaged. Settle somewhere you can safely close your eyes.
- Open one individual pouch when you are ready. Warming starts on opening, so use it promptly rather than unpacking it well in advance.
- Separate the ear loops along the perforation and hook them over your ears. Keep your eyes closed. Do not press on your eyes through the mask to make it fit more tightly.
- Take it off immediately if it feels too hot, painful or otherwise uncomfortable. Around 20 minutes is not a target you must endure. Once heating has finished, the mask cannot be reused or reheated in a microwave.
Do not combine it with under-eye treatment sheets or similar packs. After eye drops, wait a while before using it and follow the drops’ own instructions. If you are unsure how long to wait, show your eye drops to a pharmacist and ask. Makeup may come off, so plan your break for a time when that will not bother you.
Can you wear contact lenses?
Kao’s FAQ says yes. This includes coloured lenses, provided you use them correctly, follow their instructions and have regular eye examinations. Do not press on your eyes through the mask.
If you are getting ready to sleep, follow your lenses’ separate restrictions on overnight wear. Permission to fall asleep in the mask does not override them. Stop if you develop pain or other discomfort and seek eye-care advice rather than using warmth to cover up symptoms.
Can you fall asleep in it?
Kao says you may sleep wearing this mask, while warning that the sheet can feel a little stiff after heating ends. The eye area is delicate; remove it if it becomes uncomfortable. There is no need to deliberately keep a cooled mask on all night.
The standard product here is labelled for around 20 minutes of comfortable warmth. The separately named メディカルアイケアマスク, or Medical Eye Care Mask, is another product. If that is the one you bought, follow its own instructions. Match the full name on the pack you bought.
Disposal and storage
Allow the mask to cool completely, then follow local waste rules. In Japan, Kao says to sort it like a disposable hand warmer. Never reuse a damaged or spent mask, and never microwave it. Keep the individual pouch away from electrical sockets because Kao warns of a fire risk from contact.
Keep unused masks sealed in their individual pouches, away from direct sunlight, high temperatures and heaters, and out of reach of small children or people who need supervision. Avoid puncturing the pouches: damage may prevent proper heating.
A quick check before checkout
- Match めぐりズム, 蒸気めぐるアイマスク and 無香料 for this unscented product.
- Check the count: five or twelve masks does not mean a different intended temperature.
- Keep eyes closed without pressure; remove immediately if uncomfortable.
- Stop further use and consult a doctor if a rash develops or redness or itching persists.
Browse more Japanese drugstore guides
Manufacturer sources
Checked 11 October 2026 against Kao’s Japanese information. Read the complete instructions on your own pack before use.
