Sunglasses and UV: protecting your eyes from early cataract
Choosing the right sunglasses is not just a matter of aesthetics. Cumulative UV exposure is one of the best-documented causes of early cataract, pterygium and photokeratitis. Here, in practical terms, is how to recognise effective protection and who particularly deserves to be protected.
UNDERSTANDING THE RISK
Why does UV damage the eyes?
The solar radiation that reaches the ground contains three main categories of ultraviolet light: UV-C (entirely filtered by the ozone layer), UV-B and UV-A. The latter two reach the Earth’s surface and interact with ocular tissues.
| Type | Wavelength | Penetration | Ocular targets |
|---|---|---|---|
| UV-B | 280-315 nm | Cornea + lens (little retina) | Cornea (photokeratitis, pterygium), lens (cortical cataract) |
| UV-A | 315-400 nm | Deeper, reaching the retina | Lens, retina (particularly in young subjects) |
| UV-C | 100-280 nm | Filtered by the atmosphere | None (except artificial exposure) |
Three main ocular targets
- Cornea: acute photokeratitis (“corneal sunburn”), pterygium, pinguecula with chronic exposure.
- Lens: progressive opacification (cataract), particularly of the cortical and posterior subcapsular types.
- Retina: a debated but plausible role in AMD and certain acute photochemical injuries (solar retinopathy after an eclipse, for example).
SCIENTIFIC DATA
Cataract and UV: what does science say?
The link between chronic sun exposure and cataract is one of the best documented in epidemiological ophthalmology. A systematic review published in Acta Ophthalmologica analysed all the available studies and concluded that there is a significant association between occupational exposure to solar UV and cortical cataract, particularly among outdoor workers (farmers, sailors, construction workers) (Modenese & Gobba, Acta Ophthalmol, 2018).
More specifically:
- Cortical cataract is the form most clearly linked to UV, with an increased relative risk in heavily exposed subjects.
- Posterior subcapsular cataract is also associated with cumulative UV exposure.
- An epidemiological review confirmed that UV is a risk factor independent of other determinants (age, diabetes, smoking) (McCarty & Taylor, Dev Ophthalmol, 2002).
OTHER UV CONDITIONS
Not just cataract: three other UV conditions
Photokeratitis (“corneal sunburn”)
Acute exposure to intense UV (snow, mountains, reflective water, welding) causes a painful inflammation of the cornea 6 to 12 hours later. Symptoms: a gritty sensation, watering, marked photophobia, temporary loss of visual acuity. Recovery is generally spontaneous within 24 to 48 hours with lubricants and visual rest.
Pterygium
A fibrovascular conjunctival growth that progressively encroaches onto the cornea. The link with chronic UV exposure has long been established, with a dose-response relationship documented by Australian studies (Threlfall & English, Am J Ophthalmol, 1999). Definitive treatment is surgical in the event of functional or cosmetic discomfort.
AMD and blue light
The role of UV and blue light in age-related macular degeneration remains debated. A meta-analysis nevertheless showed a moderate but significant association between cumulative sun exposure and the risk of early AMD (Sui et al., Br J Ophthalmol, 2013). Sun protection is therefore also relevant on this retinal front.
CHOOSING YOUR SUNGLASSES
Choosing the right sunglasses: 4 criteria
1. CE standard and protection category
Every product sold in Europe must display the CE marking and indicate a filtration category from 0 to 4. The category corresponds to the percentage of visible light filtered — not directly to UV, but in practice compliant manufacturers filter ≥ 99% of UV-A and UV-B from category 2 onwards.
| CE category | Visible light filtration | Use case |
|---|---|---|
| 0 | 0-19% | Aesthetic only (indoors, low light) |
| 1 | 20-56% | Overcast sky, early/late in the day |
| 2 | 57-81% | Medium brightness (spring, autumn) |
| 3 | 82-91% | Sunny summer, beach, city — recommended choice in France |
| 4 | 92-97% | High mountains, snow, sailing at sea — incompatible with driving |
2. UV 400 marking
More rigorous than the CE standard alone, the UV 400 marking ensures that the lens filters 100% of radiation up to 400 nm (so UV-A + UV-B + part of the violet light). Always to be preferred, particularly for children and subjects exposed outdoors.
3. Wraparound shape
The best filtration is useless if light gets in from the sides. A wraparound frame (marked lateral curvature, thick temples or side inserts) blocks oblique UV and diffuse light. Particularly recommended at the beach, in the mountains and for subjects with a history of pterygium.
4. Lens colour
Lens colour influences comfort and colour rendering, not UV filtration (which depends on the treatment, not the tint). In practice:
- Grey: the most faithful colour reproduction, versatile
- Brown/amber: increased contrast, pleasant when driving and on the water
- Green: a good visual-comfort compromise
- Blue/pink: attractive but distorts colours (to be avoided when driving)
WHO TO PROTECT FIRST
Particularly exposed profiles
- Children and adolescents: a young lens lets more UV through to the retina. A large part of lifetime cumulative UV exposure occurs before age 18.
- High-albedo activities: snow (reflection ≈ 80%), seawater, light-coloured sand, light-coloured asphalt.
- Outdoor occupations: farmers, sailors, construction workers, gardeners, sports instructors.
- Drug-induced photosensitivity: tetracyclines, ciclosporin, certain diuretics, amiodarone.
- History of pterygium or early familial cataract.
FAQ
Frequently asked questions
Should you wear sunglasses in winter?
Yes, particularly in the mountains (snow glare, altitude) and under a partly cloudy sky (UV passes through clouds at 70-80%). A category 2 or 3 remains relevant all year round for driving or prolonged outdoor activity.
Do cheap sunglasses really filter UV?
Yes, provided they display the CE marking and ideally the UV 400 mention. A correctly labelled €15-20 pair filters UV just as well as a luxury model. Be wary, however, of unmarked models sold without a standard — they may dilate the pupil (dark-visor effect) without blocking UV, thus worsening retinal exposure.
From what age should you protect a child?
From the first prolonged exposure (a pushchair at the beach, a first outing in the mountains). A child’s lens is still very transparent and lets more UV through to the retina than an adult’s. Choose glasses suited to paediatric morphology, marked UV 400 and category 3.
Do polarised lenses protect better against UV?
No more, no less. Polarisation is an anti-glare filter that removes horizontal reflections (water, car bonnet, wet road). It has no additional effect on UV. Increased comfort in intense outdoor light, neutral on long-term ocular risk.
My contact lenses filter UV: do I still need glasses?
Yes. UV-filtering lenses (class 1 or 2) cover only the central cornea. They protect neither the conjunctiva (pterygium), nor the eyelids, nor the laterally exposed sclera. Glasses remain the reference measure; UV lenses are a useful complement, not a substitute.
Should you wear glasses after cataract surgery?
Yes, particularly in the first few weeks (increased light sensitivity) and in the long term. Most modern intraocular implants include a UV filter, but protect only the implanted zone. The remaining structures (cornea, conjunctiva, eyelids) benefit from the protection of glasses.
Can you look at a solar eclipse with very dark sunglasses?
Never. No sunglasses, even category 4, protect against directly observing the sun. An exposure of a few seconds can cause solar retinopathy (macular burn) with permanent damage. Only glasses certified to ISO 12312-2 allow observation of an eclipse, and only under the conditions specified by their manufacturer.
NEXT STEP
Unsure about the state of your lens?
A consultation at the practice makes it possible to assess the transparency of your lenses (early signs of cataract) and the state of your conjunctiva (early pterygium). Examination without systematic dilation, lasting 20 to 30 minutes.
Cachan practice — 1 ter rue Camille Desmoulins · Tel. 01 45 47 08 11
Scientific sources
- Modenese A, Gobba F. Cataract frequency and subtypes involved in workers assessed for their solar radiation exposure: a systematic review. Acta Ophthalmologica. 2018. PMID: 29682903.
- McCarty CA, Taylor HR. A review of the epidemiologic evidence linking ultraviolet radiation and cataracts. Developments in Ophthalmology. 2002. PMID: 12061276.
- Threlfall TJ, English DR. Sun exposure and pterygium of the eye: a dose-response curve. American Journal of Ophthalmology. 1999. PMID: 10511020.
- Sui GY, Liu GC, Liu GY, et al. Is sunlight exposure a risk factor for age-related macular degeneration? A systematic review and meta-analysis. British Journal of Ophthalmology. 2013. PMID: 23143904.
- Yam JC, Kwok AK. Ultraviolet light and ocular diseases. International Ophthalmology. 2014. PMID: 23722672.
Going further
- Cataract surgery — understanding the condition and its treatment
- Dr Tourabaly — background and technical facilities
- Book an appointment — Cachan or Paris 13
This article is for information purposes. A personalised ophthalmological opinion remains essential for any treatment decision.
Written and reviewed by Dr Moïse Tourabaly, ophthalmic refractive surgeon — former chief resident (Quinze-Vingts National Eye Hospital).
Last updated: July 6, 2026
