Introduction

If you’ve ever come home from skiing, welding, or spending hours on the beach and suddenly noticed painful, red, watery eyes, you might have experienced photokeratoconjunctivitis. This condition, also called photokeratitis or “sunburn of the eye,” is caused by unprotected exposure to ultraviolet (UV) light.

It affects both the cornea (the clear front part of the eye) and the conjunctiva (the thin membrane covering the white of the eye). Symptoms can range from mild irritation to severe pain and temporary vision loss. The good news is that, in most cases, it heals completely within a few days with proper care.¹

Understanding what causes it, who is at risk, and how to treat and prevent it is key to protecting your vision.

What is Photokeratoconjunctivitis?

Photokeratoconjunctivitis is an acute inflammatory reaction triggered by excessive exposure to UV radiation. It is sometimes known as:

• Snow blindness – when caused by reflected sunlight on snow
• Arc eye – when caused by welding arcs
• Welder’s flash – another occupational term

Regardless of the source, the mechanism is the same: UV light damages the outer cells of the cornea and conjunctiva, causing pain, redness, tearing, and blurred vision.²

How UV light damages the eye

The cornea absorbs nearly all UV-C (100–280 nm) and most UV-B (280–315 nm) rays, which protects deeper structures but leaves the surface at risk of injury. Excess exposure leads to:

• DNA damage in corneal epithelial cells
• Cell death and peeling of the surface layer
• Exposed nerve endings, causing severe pain and light sensitivity
• Conjunctival inflammation, adding redness and swelling^3,4

Interestingly, symptoms do not appear immediately. They typically develop 6–12 hours after exposure, once the protective surface cells are shed.

Causes and risk factors

Photokeratoconjunctivitis can be caused by natural or artificial UV light:

• Sunlight reflected off snow, ice, water, or sand – fresh snow reflects up to 90% of UV rays, dramatically increasing exposure¹
• High altitude – thinner atmosphere means stronger UV radiation
• Arc welding – welders without adequate shielding are highly vulnerable (“arc eye”)
• Tanning beds and sunlamps – emit concentrated UV-A and UV-B radiation³
• Germicidal UV-C lamps – increasingly used for disinfection in homes and workplaces⁶
• Solar eclipses – looking directly at the sun without protection can damage both cornea and retina⁵

Risk factors include:

• Not wearing proper eye protection (sunglasses, goggles, face shields)
• Outdoor activities at high altitude or on reflective surfaces
• Occupational exposure (welders, lab and healthcare workers)
• Recreational use of tanning beds or UV lamps

Signs and symptoms

Typical symptoms appear several hours after exposure and may include:

• Severe eye pain or burning
• Redness of both eyes
• Excessive tearing
• Sensitivity to light (photophobia)
• Blurred vision or halos around lights
• Eyelid swelling
• Headache
• Foreign body sensation, as though “sand is in the eye”

Symptoms usually resolve within 24–72 hours with supportive care.⁷

Diagnosis

Doctors diagnose photokeratoconjunctivitis by combining history and eye examination:

• History – recent UV exposure (skiing, welding, tanning, UV lamps) and delayed onset of symptoms
• Fluorescein dye test – reveals small punctate erosions on the cornea
• Slit-lamp examination – to check for inflammation, swelling, or erosions
• Differential diagnosis – conditions like viral conjunctivitis, dry eye, or chemical exposure need to be ruled out^2,7

Diagnosis

Doctors diagnose photokeratoconjunctivitis by combining history and eye examination:

• History – recent UV exposure (skiing, welding, tanning, UV lamps) and delayed onset of symptoms
• Fluorescein dye test – reveals small punctate erosions on the cornea
• Slit-lamp examination – to check for inflammation, swelling, or erosions
• Differential diagnosis – conditions like viral conjunctivitis, dry eye, or chemical exposure need to be ruled out^2,7

Prevention

Preventing photokeratoconjunctivitis is straightforward:

• Wear sunglasses blocking 99–100% of UVA and UVB rays. Wrap-around styles are best^1,5
• Use protective goggles or face shields when welding or working with UV lamps
• Wear a wide-brimmed hat outdoors
• Consider UV-blocking contact lenses if you spend long hours outside
• Never look directly at UV-emitting devices or the sun without proper protection⁶

New trends and risks

Modern lifestyles have introduced new risks:

• COVID-19 germicidal lamps – misuse of UV-C lamps at home has caused more reported cases worldwide⁶
• Outdoor UV light displays – linked to outbreaks of photokeratitis at recreational events⁷
• Tanning bed use – especially popular among younger adults, continues to be a risk factor³

These trends highlight the need for public awareness and stronger safety guidance.

Real-world examples

• Welders: Even experienced workers may develop arc eye if protective gear slips or fails
• Skiers and mountaineers: Sudden snow blindness from reflected sunlight at altitude
• Families using UV lamps: Entire households have developed eye pain after accidental overexposure during disinfection
• Festival-goers: Cases have been reported at light shows using high-intensity UV displays⁷

FAQs

How long does photokeratoconjunctivitis last?

Most cases heal completely within 24–72 hours with rest and supportive care.^4,7

Can it cause permanent vision loss?

Permanent damage is very rare. However, repeated or severe exposure increases the risk of long-term eye problems like cataracts.⁶

Is it contagious?

No. It is not caused by infection and cannot be passed from person to person.

What’s the difference between photokeratitis and snow blindness?

Snow blindness is a specific type of photokeratitis caused by sunlight reflected from snow or ice.¹

Are children more at risk?

Yes. Children’s eyes are more sensitive to UV light, and they may be less likely to wear protective eyewear.⁶

Summary

Photokeratoconjunctivitis is a painful but temporary inflammation of the cornea and conjunctiva caused by UV light exposure. Symptoms like pain, redness, tearing, and light sensitivity usually appear hours after exposure and resolve within a few days.

Treatment focuses on supportive care—resting in a dark room, using artificial tears, applying cold compresses, and avoiding further UV exposure. Prevention, through sunglasses, goggles, and protective measures, is the best approach.

With greater awareness of both natural and artificial UV sources, especially germicidal lamps and tanning devices, individuals can take simple steps to protect their vision for the future.