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Dr. Chrysoula I. Liakou MD, PhD
- Treated online: Yes. Snow blindness is diagnosed from the symptoms and the UV exposure, and a doctor can assess it by video.
- What it is: photokeratitis, a sunburn of the surface of the eye from unprotected UV light, often reflected off snow, water or sand.
- Symptoms: pain, a gritty feeling, redness, watering, blurred vision and sensitivity to light, typically 6 to 12 hours after exposure.
- Usual course: symptoms usually settle within 24 to 48 hours, usually with no permanent damage.
- Emergency: call 112 or go to an emergency department if you suddenly cannot see, or after a chemical splash or a high-speed injury to the eye.
Do not book a video appointment if you suddenly cannot see from one or both eyes, a strong chemical has splashed into your eye, something has pierced the eye or hit it at high speed, or your sight has changed after an injury. Go to an emergency department or call 112. After a chemical splash, rinse the eye with lukewarm running water for at least 20 minutes while you wait.
Can an online doctor treat snow blindness?
Yes. Snow blindness is diagnosed from the symptoms and the UV exposure before them, and both work by video. The doctor asks about the hours on snow, water or sand, looks at your eyes on camera, and checks for signs of another eye problem that needs an examination. Most snow blindness heals on its own within a day or two, and the doctor helps you through it comfortably.
How an online consultation helps with snow blindness
- The cause made clear: Snow, water, sand, a sunbed or welding: the story of the exposure usually makes the cause clear.
- Other eye problems ruled out: Viral conjunctivitis, contact lens problems, dry eye and a speck in the eye can cause similar symptoms and need different care.
- Relief while the eye heals: Lubricating eye drops, pain relief and practical steps to rest the eyes, chosen after the doctor checks your other medicines.
- Protection for the rest of the trip: Which sunglasses or goggles to wear, and when you can go back on the snow or the water.
What the doctor checks in an online snow blindness consultation
The consultation follows a fixed order, and the emergency signs come first. The doctor asks about:
- Emergency signs: sudden loss of sight, an injury to the eye, or a chemical splash.
- The exposure: hours on snow, water or sand, and whether you wore sunglasses or goggles.
- The symptoms: pain, grittiness, watering, redness, swollen eyelids, sensitivity to light and blurred vision, and when they started.
- Contact lenses: whether you wear them, and for how long you wore them that day.
- Your eyes and health: earlier eye problems or eye surgery, and the medicines you take.
Before the call, take out any contact lenses, and sit in a dimly lit room facing a soft light so the doctor can see your eyes without discomfort.
What is snow blindness?
Snow blindness, or photokeratitis, is damage to the surface of the cornea, the clear front window of the eye, caused by unprotected exposure to ultraviolet (UV) light. It is like sunburn of the eye. Snow, water, sand and concrete reflect sunlight back towards the eyes, which is why it often follows a day of skiing, mountaineering or sailing without good eye protection.
The same injury can come from a tanning lamp, or from a welding arc, when it is often called arc eye.
Why is snow blindness more likely in the mountains?
Because UV is stronger at altitude and snow reflects it back into the eyes. Thinner air absorbs less UV, so levels rise the higher you go, and fresh snow, water and sand all increase the UV reaching your eyes. That is why snow blindness is more common in high mountains and near the poles, and why skiers, snowboarders and mountaineers are most at risk.
- Cloud does not protect you: UV is highest under clear skies but can still be high under cloud, so wear eye protection on grey days too.
- No warning: you feel nothing while the damage happens, and the longer the exposure, the worse the symptoms hours later.
- The UV index: sun protection, sunglasses included, is recommended whenever the UV index reaches 3 or above. The Climate Health Index shows daily UV scores for European cities.
Snow blindness symptoms
Symptoms usually affect both eyes:
- pain and irritation, often like grit or sand in the eyes
- red, watering eyes
- sensitivity to light
- eyelids that twitch or clamp shut
- blurred vision, and haloes around lights
- red, swollen eyelids
- a headache
They typically start 6 to 12 hours after the exposure, so they often appear in the evening or overnight after a day outdoors. Rarely, colour vision changes for a short time. The damage itself is on the surface of the cornea: in an eye examination, dye drops show where it is.
How long does snow blindness last?
Symptoms usually settle within 24 to 48 hours, and there is usually no permanent damage. Mild blurring or sensitivity to light can continue for up to a week or longer.
Swipe sideways to compare →
| When | What happens | What helps |
|---|---|---|
| During the exposure | Usually no symptoms: the damage happens without warning | Sunglasses or goggles all day |
| 6 to 12 hours later | Pain, grittiness, watering and sensitivity to light begin | Rest, cold compresses, lubricating drops, pain relief |
| By the next day | The surface of the eye is mostly healed | Keep resting the eyes and avoid strong sun |
| Within 24 to 48 hours | Symptoms usually settle | See a doctor if they are not settling |
| Up to a week or longer | Mild blurring or light sensitivity can linger | Sunglasses, and no contact lenses until healed |
How to treat snow blindness
The surface of the eye heals by itself. These steps keep you comfortable while it does:
- Get out of the sun, and avoid any more UV exposure.
- Take out contact lenses, and leave them out until the eye has fully healed.
- Rest with your eyes closed, and put a cold compress over the closed eyelids.
- Wear sunglasses for comfort, indoors and out.
- Use lubricating eye drops, ideally preservative-free, for comfort.
- Take paracetamol or ibuprofen for the pain.
Snow blindness or something else?
Other eye problems can cause pain, redness and watering. These patterns help tell them apart:
Swipe sideways to compare →
| Condition | What points to it | Read more |
|---|---|---|
| Snow blindness | Both eyes painful and gritty 6 to 12 hours after hours of strong sun on snow, water or sand | This page |
| Conjunctivitis | Red, sticky or watery eyes without strong UV exposure, often starting in one eye | Conjunctivitis |
| Keratitis | A painful red eye with blurred vision, especially in contact lens wearers | Keratitis |
| Dry eye | Gritty, tired eyes that are worse with wind, screens and air conditioning | Dry eye |
| Something in the eye | Pain in one eye after something blew or flew into it | An eye check if it does not wash out |
| A burn of the retina | Problems with your sight after looking at the sun or a solar eclipse without a proper filter; it lasts longer and is more serious | An eye examination promptly |
How to protect your eyes on snow and water
Snow blindness is preventable with the right eye protection:
- Wear sunglasses or goggles that block 99% or more of UV, labelled 100% UV or UV 400, with the CE mark and the ISO 12312-1 standard. How dark the lenses are says nothing about their UV protection.
- Choose wraparound lenses, broad arms or side shields, which cut the UV reaching the eyes from the sides.
- Wear them all day on snow, on the water and on bright beaches, because snow, sand, concrete and water reflect sunlight.
- Carry a spare pair on long ski tours, mountain trips and sailing days.
- Never look directly at the sun.
Swipe sideways to compare →
| Filter category | Suitable for | Driving |
|---|---|---|
| 0 and 1 | Not suitable as sunglasses | Not relevant |
| 2 | Everyday use | Not at night, at dusk or in poor light |
| 3 | Everyday use, holidays and sunny places such as the mountains or the beach | Not at night, at dusk or in poor light |
| 4 | Extreme glare: at sea, in the desert, high in the mountains and over snowfields; side protection required | Never: too dark to recognise traffic lights |
Why eye protection matters beyond snow blindness
Snow blindness heals, but years of UV exposure harm the eyes in other ways. UV contributes to cataracts: of an estimated 15 million people worldwide who are blind from cataracts, about 10% may owe it to UV. It also contributes to pterygium, a growth of fleshy tissue that can cover part of the cornea.
Which snow blindness treatment might the doctor recommend?
Treatment depends on how severe the symptoms are and how quickly they settle. This is the framework the doctors use, in line with UK optometry and NHS eyecare guidance.
Swipe sideways to compare →
| What you have | Likely first step | Suitable for online care? | When in-person care is needed |
|---|---|---|---|
| Painful, gritty eyes after UV exposure | Rest, cold compresses, lubricating drops and pain relief | Yes | Not usually needed |
| Severe pain, or eyelids clamping shut | An eye examination, and sometimes drops that relax the eye’s focusing muscle | Partly | For the eye examination |
| Symptoms not settling after 48 hours, or vision still blurred | An eye examination to check healing and rule out other causes | Partly | For the examination |
| A painful red eye in a contact lens wearer | An eye examination to rule out infection | Partly | Promptly, in person |
| Sudden loss of sight, or a chemical or high-speed injury | Emergency treatment | No | Call 112 or go to an emergency department now |
Painful eyes after a day on the snow? A doctor can tell you in one consultation what to do.
See available times →Treatment options for snow blindness
What you can do yourself
- Stay out of the sun, and rest with your eyes closed.
- Use a cold compress and lubricating eye drops for comfort.
- Take paracetamol or ibuprofen for the pain.
- Leave contact lenses out until the eye has fully healed.
Prescription treatment
A prescription is never issued without a consultation. Most snow blindness needs only lubricating drops and pain relief. When the surface of the eye is badly damaged, an optometrist or eye specialist may examine it and add antibiotic drops or ointment to prevent infection, or drops that ease painful spasm of the eye’s focusing muscle. If the doctor prescribes, use the prescription at a pharmacy near you.
What does not help
Numbing eye drops are used only to help examine the eye, not to treat the pain. Contact lenses and more strong sun without eye protection are best avoided until the eye has healed.
Special situations
Skiing and mountaineering
Snow reflects sunlight strongly. Wear goggles or wraparound sunglasses all day on the slopes, and protect your skin as well: see the sunburn page. A headache and nausea at height are covered on the altitude sickness page, and other holiday health problems on the travel illnesses page.
Sailing and beach holidays
Water and sand reflect sunlight too, so wear sunglasses on boats and on bright beaches.
Sunbeds and welding
Tanning lamps and welding arcs cause the same injury. Use the eye protection provided, every time.
Contact lenses
Leave contact lenses out until the eye has fully healed, and have a painful red eye checked promptly if you wear them.
Children
Mobi Doctor consultations are for adults aged 18 and over. A child who is unwell needs a paediatrician or a local doctor in person, and emergency signs in a child mean 112.
When snow blindness is treated online, and when you need in-person care
Treated online: snow blindness and UV eye burns after time on snow, water or sand, pain relief and eye care while they heal, and protection for the rest of the trip.
In-person care: sudden loss of sight, chemical or high-speed eye injuries, symptoms that do not settle within 48 hours, and an eye that needs examining.
When to get in-person care
Call 112 or go to an emergency department now for:
- sudden loss of sight in one or both eyes
- a strong chemical in the eye: rinse it with lukewarm running water for at least 20 minutes while you wait
- something that has pierced the eye or hit it at high speed
- any change in your sight after an eye injury
- flashing lights with a dark shadow or curtain moving across your vision
Get medical advice the same day for:
- changes in your vision, such as blurred or double vision
- eye pain that is getting worse rather than better
- symptoms that have not started to settle after 24 to 48 hours
- a painful red eye if you wear contact lenses
How Mobi Doctor works
- Book a time that suits you: daily 7am–11pm CEST. You can see a doctor over video, usually within 15 minutes. No subscription, and the exact price is shown before you pay.
- Speak to a licensed doctor about your eyes: say how long you were on the snow or the water, whether you wore sunglasses, and when the pain started.
- Leave with a plan: what to do, what to take and for how long, and which signs mean you should be seen in person. If the doctor prescribes, use the prescription at a pharmacy near you.
No sign-up needed
Not sure it’s snow blindness? Tick every symptom you have to see each condition page that mentions it. It finds the right page, not a diagnosis: a doctor gives you that on a video call.
Tap the body — an area or a point — to browse symptoms anywhere
Similar symptoms, different condition? Conjunctivitis can start the same way. Compare them, or look up any other symptom in the full symptom checker.
Frequently asked questions about snow blindness
What does snow blindness feel like?
Snow blindness feels like grit or sand in the eyes, with pain, redness, watering and sensitivity to light. The eyelids may twitch or clamp shut, vision may be blurred, and the eyelids can look red and swollen.
How long does snow blindness last?
Snow blindness symptoms usually settle within 24 to 48 hours, usually with no permanent damage. Mild blurring or sensitivity to light can last up to a week. See a doctor if the symptoms are not settling.
How long after sun exposure does snow blindness start?
Snow blindness symptoms typically start 6 to 12 hours after the exposure, so they often appear in the evening or overnight after a day on snow, water or sand.
How do you treat snow blindness at home?
For snow blindness, stay out of the sun, take out contact lenses, rest with your eyes closed and a cold compress over them, use lubricating eye drops, and take paracetamol or ibuprofen for the pain. Most cases heal on their own within a day or two.
Is snow blindness permanent?
Usually not. Snow blindness goes away by itself, usually within 24 to 48 hours, because the surface of the eye heals quickly, and there is usually no lasting damage. Symptoms that do not settle need an eye examination.
What does snow blindness look like?
With snow blindness the eyes look red, bloodshot and watery, the eyelids can be puffy and swollen, and the person squints or keeps the eyes closed in light. The damage to the surface of the eye shows up only with dye drops during an eye examination.
Can you get snow blindness on a cloudy day?
Yes. UV is highest under clear skies but can still be high under cloud, and snow reflects it back into the eyes, so snow blindness can follow a grey day too; wear sunglasses or goggles on grey days in the mountains too.
Can you get snow blindness without snow?
Yes. The same injury as snow blindness, photokeratitis, can follow sunlight reflected off water or sand, a tanning lamp, or a welding arc, when it is called arc eye.
Which sunglasses prevent snow blindness?
To prevent snow blindness, choose sunglasses or goggles that block 99% or more of UV, labelled 100% UV or UV 400 with the CE mark, with wraparound lenses or wide arms. Filter category 3 suits the mountains, and category 4 suits extreme glare over snowfields but is too dark for driving.
Can I wear contact lenses with snow blindness?
No. Take contact lenses out as soon as snow blindness starts and leave them out until the eye has fully healed, usually 2 to 3 days, because the damaged corneal surface is prone to infection and a lens rubs on it and slows healing; wear glasses in the meantime, and if a lens is stuck or very painful to remove, get help rather than forcing it. Never sleep in lenses while the eye is recovering.
Can an online doctor treat snow blindness?
Yes. A doctor can assess snow blindness symptoms and the UV exposure by video, rule out other eye problems, and recommend treatment for the pain. Sudden loss of sight or an eye injury needs emergency care.
- Photokeratitis (ultraviolet [UV] burn, arc eye, snow blindness), The College of Optometrists, Clinical Management Guidelines, 2025.
- 5.16 Photokeratitis (ultraviolet burn, arc eye, snow blindness), NHS Scotland Eyecare Guidelines, 2026.
- Sunscreen and sun safety, NHS, National Health Service (UK), reviewed 24 March 2026.
- Vision loss, NHS, National Health Service (UK), reviewed 28 August 2025.
- Eye injuries, NHS, National Health Service (UK), reviewed 12 March 2026.
- What is photokeratitis, including snow blindness?, American Academy of Ophthalmology, 16 May 2023.
- Ultraviolet radiation: fact sheet, WHO, World Health Organization, 21 June 2022.
- Factsheet: sunglasses for general use, Federal Office of Public Health (FOPH), Switzerland, October 2024.
- What is snow blindness and how can you prevent it?, University of Utah Health, Moran Eye Center, 20 January 2020.
This page is for information only and is not a substitute for a medical consultation. Guideline links are provided for transparency; treatment decisions are made with your doctor.
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