Do sunglasses increase sunburn risk? And how to treat a sunburn

A claim circulating on social media says that wearing sunglasses increases the risk of sunburn, because it stops the eyes signalling to the body that the sun is out. This is not true. Melanin production in the skin is triggered locally by ultraviolet radiation reaching the skin itself, not by a visual signal. Going without sunglasses does not protect your skin, and it exposes your eyes to radiation that causes cataracts, macular degeneration and eyelid skin cancer. A sunburn takes three to seven days to settle and is treated with cooling, moisturising and pain relief — extensive blistering or fever needs medical assessment.

Do sunglasses increase the risk of sunburn?

No. The myth rests on a misunderstanding of how tanning works.

The version doing the rounds says the eyes detect sunlight and send the brain a signal that activates melanin production, and that dark lenses block that signal, leaving the skin unprotected.

What actually happens is different. Melanin is produced by melanocytes in the skin in direct response to ultraviolet radiation reaching the skin itself. It is a local mechanism, defending against DNA damage in skin cells. It does not depend on the eyes.

There is indeed a neuroendocrine pathway responding to light through the retina, linked to circadian rhythm and melatonin production. But that pathway does not regulate skin pigmentation in any clinically relevant way, and no study has shown that wearing sunglasses increases burning.

There is also this: melanin, even once produced, offers protection equivalent to a low sun factor. Tanning is not protection — a tan is the visible mark of DNA damage that has already happened.

What are sunglasses actually for?

They protect structures that do not regenerate.

The lens of the eye. Cumulative ultraviolet exposure is an established risk factor for cataracts, one of the leading causes of vision loss worldwide.

The retina. Radiation contributes to age-related macular degeneration.

The ocular surface. It causes pterygium — tissue growing over the cornea, more common in outdoor workers — and actinic keratitis, a corneal burn causing intense pain and grittiness hours after strong exposure, typical of snow and sea.

The eyelids. Periocular skin is among the thinnest on the body and a frequent site of basal cell carcinoma. Eyelids account for a significant proportion of facial skin cancers, and are among the areas where people least often apply sunscreen.

Which sunglasses should you choose?

Lens colour and darkness tell you nothing about protection. A dark lens with no UV filter is worse than no sunglasses at all: the pupil dilates in the shade and lets in more radiation.

What to require:

• UV400 or “100% UV protection” — blocking radiation up to 400 nanometres, meaning UVA and UVB

• CE marking, mandatory in the European area

• A filter category suited to the use

• Large lenses or side protection, because radiation enters from the sides and reflects off the inner surface of the lens

The categories, 0 to 4:

• Category 0 — very light lenses, decorative or indoor use. Minimal protection

• Category 1 — low light, overcast days

• Category 2 — medium light

• Category 3 — the most common, and the right choice for strong sun, the beach and general summer use

• Category 4 — very dark, for high mountains and glaciers. Not permitted for driving

Polarised is a different matter: it reduces glare from reflective surfaces such as water, snow or asphalt. It improves comfort and clarity, but adds no UV protection in itself. Polarised lenses without UV400 do not protect.

For children, the same requirements apply. Radiation accumulated in childhood weighs on lifetime risk, and a child's lens is more transparent, letting more radiation through to the retina.

How do I treat sunburn quickly?

There is no way to substantially speed up repair, but there is a way to reduce discomfort and avoid complications.

In the first hours: get out of the sun. Cool with a cool — not cold — shower or damp compresses, fifteen minutes, several times a day.

Moisturise generously with a fragrance-free cream or lotion, while the skin is still damp. Products with aloe vera or dexpanthenol give symptomatic relief.

Drink more water. Extensive burning causes fluid loss and can lead to dehydration.

Pain relief. An oral anti-inflammatory in the first hours reduces pain and inflammation, if there is no contraindication.

Do not use: butter, olive oil, toothpaste, vinegar, ice directly on the skin, or topical anaesthetics containing benzocaine, which frequently cause allergy. None help and several make things worse.

Do not burst blisters. The skin covering them is the barrier against infection.

Do not re-expose the area to sun until fully recovered.

How long does sunburn take to heal?

It depends on the depth.

First-degree burn — redness, heat, pain, no blisters. Improves in three to five days, with peeling from day three or four.

Superficial second-degree burn — with blisters. Takes one to three weeks and can leave temporary pigment change.

Peeling is normal and part of repair. Do not pull off peeling skin: letting it come away on its own reduces the risk of marking.

Redness can give way to post-inflammatory hyperpigmentation, which takes weeks to months to fade, particularly in higher skin types.

Sunburn with blisters: when is it serious?

Blisters indicate a second-degree burn. One or two over a small area usually settles with the care described.

Seek medical care if there is:

• Extensive blistering, particularly over a large area of the body

• Fever, chills, nausea, vomiting or dizziness

• Severe headache, confusion or fainting — these can indicate heatstroke

• Signs of infection: pus, increasing pain, spreading redness, red streaks

• Burning on the face, hands, genitals or major joints

• Burning in a baby or young child

• Burning in someone immunosuppressed or taking photosensitising drugs

Why does sunburn itch?

Itching accompanies the repair phase and peeling, and results from inflammatory mediators such as histamine being released.

There is an intense form, sometimes called hell's itch, appearing one to three days after a strong burn and causing deep, unbearable itching that responds poorly to the usual measures. It is uncomfortable but self-limiting, and improves with intensive moisturising, cooling and, in some cases, prescribed medication.

Itching accompanied by a rash on exposed areas, particularly if recurrent, may indicate polymorphic light eruption or a photosensitivity reaction to a medication, rather than simple sunburn.

What is left afterwards

The burn heals. The damage does not entirely disappear.

Every sunburn raises lifetime skin cancer risk, and blistering sunburns in childhood and adolescence are a particularly strong risk factor for melanoma.

Damage accumulates silently. It contributes to photoageing, to pigmentation and to actinic keratoses, which are premalignant lesions.

Anyone who has had severe burns, particularly as a child, benefits from regular mole surveillance.

When to see a dermatologist?

• After sunburns with blisters, particularly if repeated

• When a mark, crust or sore that will not heal appears on a highly exposed area

• When a mole changes in size, colour or shape

• When there is recurrent rash in the sun

• When you had blistering burns in childhood — for mole mapping

• When you have skin type I or II and have never been screened

Dr Ellene Papazis is a dermatologist accredited in Portugal and Brazil, with training in cutaneous oncology, and performs mole mapping in Porto, Portugal.

Sources

• American Academy of Dermatology — sunburn treatment and prevention

• World Health Organization — Ultraviolet radiation and health

• EN ISO 12312-1 — filter categories for sunglasses

• Portuguese Society of Dermatology and Venereology (SPDV)

Written and reviewed by Dr Ellene Papazis, dermatologist accredited in Portugal and Brazil. Consultations in Porto, Portugal.

Updated 25 July 2026.