Photokeratitis: how UV light can sunburn your eyes
Most people think about UV and skin. Your eyes can burn too. Photokeratitis is an inflammation of the cornea caused by ultraviolet light, and it often shows up hours after the exposure, when it's too late to put on sunglasses.
- UV radiation can cause inflammatory reactions in the eye, especially the cornea; UV-induced keratitis is a well-known result.
- In one review, UV at 300 nm caused apoptosis in all three layers of the cornea, seen 5 hours after exposure.
- Solar elevation is the most important factor in how much UV reaches the ground; altitude, ground reflection, latitude and season also matter.
- Artificial UV sources matter too: case reports describe clusters after UV lamps at a nightclub and at home with UVC disinfection lamps.
What it is
A review in Cullen, Int J Toxicol 2002 (PMID 12537642) explains that the cornea and exposed conjunctiva face the environment whenever we're awake, and that solar UV reaching the eye "may exceed the damage threshold under a number of circumstances." The early clinical signs of photokeratitis are due to lost or damaged surface cells of the cornea. Chronic solar UV exposure is also a factor in pterygium.
Why travel and outdoor sports raise the risk
A review of the literature in Izadi et al., J Postgrad Med 2018 (PMID 29067921) found that UV "at 300 nm causes apoptosis in all three layers of the cornea and induces keratitis," with changes appearing 5 hours after exposure. The authors list factors that change UV intensity at the eye, including solar elevation, time of day, season, clouds, ozone, latitude, altitude and ground reflection. They note that "the most important factor" is solar elevation, and that travelers are especially exposed.
Artificial UV sources
- Ting et al., Cont Lens Anterior Eye 2016 (PMID 26851136) described 22 patients who arrived at one eye clinic within 24 hours with photokeratitis after intense UV-B exposure at a nightclub. They were treated with short courses of eye drops and none returned.
- Raviv Sasportas et al., Harefuah 2024 (PMID 38734942) reported four cases of bilateral photokeratitis from improper home use of UVC disinfection lamps during the COVID-19 pandemic, and noted symptoms "usually appear a few hours after the exposure."
Prevention
The review in Izadi et al., J Postgrad Med 2018 (PMID 29067921) lists avoiding direct sunlight, "using UVR-blocking eyewear (sunglasses or contact lenses), and wearing hats" as protective measures. For skiing, beach days and high-altitude hikes, wraparound UV-blocking sunglasses or goggles matter. Never look at or work under germicidal UV lamps without proper protection. Eye pain, light sensitivity or a gritty feeling after UV exposure is a reason to see an eye doctor.
Related: sunglasses and UV eye protection and the UV index explained.
Educational information only, not medical advice. See a board-certified dermatologist or eye doctor for diagnosis and treatment. See our medical disclaimer.
Published October 31, 2026. Sources are linked in the text. See our Medical Disclaimer.