Every summer, patients walk into eye clinics in the middle of the night, convinced something has gone seriously wrong with their eyes. The pain is intense, a burning, gritty feeling as though sand is trapped under the eyelids. The eyes are red, watering heavily, and sometimes swollen. And when you ask them what happened, they struggle to answer. They went to the beach. They drove through afternoon traffic. They watched a cricket match outdoors. Nothing unusual, they say. Nothing that should have caused this.
What they have is photokeratitis. And almost none of them have heard of it before.
What exactly is photokeratitis?
Simply put, photokeratitis is a sunburn of the eye. Most people know that unprotected skin burns in strong sunlight. What they do not know is that the surface of the eye, the cornea and conjunctiva, is just as vulnerable to ultraviolet radiation. Exposure to intense UV rays, especially UVB and UVC, causes the same kind of acute damage to the eye's surface that the sun causes to skin. The difference is that nobody talks about it.
Why does it catch people off guard?
The condition has one particularly tricky feature. The damage happens silently. There is no pain, no discomfort, no warning at the time of exposure. Symptoms only appear four to twelve hours later, often in the middle of the night, long after the person has gone home and forgotten about their time outdoors. By then, the link between the afternoon in the sun and the agony at midnight is almost never made. This is why photokeratitis is so frequently mistaken for an allergy or an infection, and why it goes undiagnosed far more often than it should.
Who is most at risk?
Some people are more exposed to the risk than others. Traffic police officers, delivery workers, and outdoor commuters spend long hours in direct sunlight without any eye protection. Hikers, swimmers, and sportspeople face an added problem: UV rays bounce off water, sand, and concrete, hitting the eyes from multiple directions at once. Welders are another group at risk. A momentary exposure to an arc flash can cause a version of this condition known as welder's flash, which is more common in occupational settings than most people realise. In all these cases, it is not just how long you are exposed but how intense the UV is that determines the damage.
What to do if it happens
The good news is that photokeratitis heals on its own. The cornea regenerates quickly, and most people recover fully within 24 to 72 hours. If symptoms appear, remove contact lenses, apply a cool compress, and use preservative-free lubricating eye drops. Do not rub the eyes. The discomfort passes, and that is precisely the problem.
The risk nobody talks about
Because it heals so completely, people do not take it seriously. The episode is forgotten, nothing changes, and the next bout of unprotected sun exposure sets the same process in motion. Over time, repeated UV damage to the eyes quietly raises the risk of cataracts and macular degeneration, two of the leading causes of permanent vision loss. Neither condition announces itself early. By the time a patient notices something is wrong, the damage has often been building for years.
How to protect your eyes
Protecting the eyes is not complicated. Sunglasses with UV400 or 100% UVA/UVB protection are essential, not optional. A wide-brimmed hat helps block the sun from angles that glasses do not always cover. These are simple habits, but they make a real difference over a lifetime.
We have become good at protecting our skin from the sun. It is time we gave our eyes the same attention.
The author is a consultant ophthalmologist at Dr Agarwals Eye Hospital, Bengaluru.
The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.
