Every two hours, Jose Vega uses ointment to help his right eye, lined with two rows of stitches, heal from surgery. The cost of the ointment and the operation — his third due to pterygiums, or growths caused from excessive UVA light exposure — has put a financial strain on his family of five in Kansas City, especially as he takes a six-week leave from work without pay.

KANSAS CITY, Mo. — At 5 p.m., as Jose Vega uncaps a tiny, $100 tube of ointment, he thinks of work. As a chef at Jabinero’s, he should already be spreading ingredients — onions, peppers, meats — across the restaurant stovetop. But instead, he is spreading ointment over two rows of stitches in his eyes, and he can’t come close to that, or any stove for five more weeks.

That means for another five weeks, his wife Tanya Vega will have to keep the family of five afloat with nonstop nightly shifts at St. Luke’s Hospital on top of nursing school classes. Vega, who had his third pterygium — a layer of tissue that grows over the eye, starting at the inside corner — removed last week, has to stay clear from sun and heat that long to recover.

The pterygiums, which Vega got subjecting his eyes to too much sunlight, are just one of many problems the sun can cause in human eyes, said Vega’s surgeon Carl Stout, of Discover Vision. Others, he said, vary from a keratitis — a sun burn on the eye — to both a higher risk, and a faster onset, of more serious conditions like cataracts and macular degeneration.

The danger for all eye damage from the sun is significantly greater in the summertime. In summer, people are closer to the sun, and its light is more intense, like when people visit the equator. A number of season activities, such as water sports and games on concrete, only raise that risk by exposing people to reflected light, too.

But unfortunately, a lack of awareness on the harm of sunlight to eyes, and what people need for full protection, is also great, Stout said. As a result, doctors are trying to educate their patients in each exam.

“It’s just one more thing that we can protect ourselves from, if we’re a little aware of the problem,” said Lee Duffner, AAO correspondent and Hollywood, Fla., ophthalmologist. “If we’re totally unaware of the problem, nobody’s going to do anything.”

For Vega, the principal problem was a lack of education on personal eye care. As a boy, he played soccer daily with friends in his hometown of Guanaguanto, Mexico, without sunglasses. Later, as a young man, he picked broccoli all day on a sunny farm in Soledad, Calif., with his eyes equally unprotected.

All these years, he never knew the potential long-term effects of exposing his eyes to the sun. Eventually, his first pterygium at age 23 was simply his eyes’ natural way of saying “enough” and trying to block out any future harmful light on their own.

Before a pterygium, Vega likely had a cinguecula, or an “unsightly thickening” of the membrane, that often effects outdoor workers, like farmers and lifeguards. Then, with more exposure, that thickening worsened into the growths that Stout had to remove. Both pterygiums and cingueculas are more unique in that they are caused by UVA light that affects the conjunctiva membrane, covering the white part of the eye, Duffner said.

Of the sunlight’s three kinds of ultraviolet, or UV, light — UVA, UVB and UVC — only the last two types, common for sunglass labels, enter the atmosphere to be of concern. Most eye problems occur due to UVB light, which has a shorter wavelength that can penetrate the cornea.

Some of these conditions, like keratitis, can develop in a day or afternoon, especially at a pool or lake where water reflects the light. But the risk for most of them, and especially the more serious ones like cataracts, macular degeneration or pterygiums, rises more gradually with light exposure. Like with pterygiums, the damage is cumulative over the course of years.

“The interesting thing about a lot of UV damage that occurs as adults is you don’t really see it until adulthood,” said optometrist Jason Rogers, of Drs. Hawks, Besler & Rogers in Overland Park, Kan.

Rogers said he always recommends people exercise caution and always wear sunglasses because they often can’t properly perceive the level of harm they are doing. The cornea of the eye has more nerve endings than any other part of the body, but the damage often needs to reach the point of a keratitis for people to feel pain.

Even with a keratitis, or sunburned eye, people often can’t pinpoint the pain they do feel, Rogers said, because they’ve been swimming and assume the discomfort is due to chlorine. And if they could, he added, the study of UV damage to eyes hasn’t reached a place where they can look back and count their exposure to their current level of risk, like with sunburns, anyway.

“They just don’t know the relationship between how much exposure causes retinal damage,” Rogers said. “They know it happens, but they don’t know how much at this point will do it.”

Vega didn’t know the sun was to blame for his growths until six years after the first one began to form. As the growth grew inward, he assumed it came from too much television. In Mexico, where his home was smaller, he would always watch TV up-close, and he had seen the eyes of his friends redden with too much time in front of the screen.

But unlike his friends, Vega found his eyes didn’t improve when he would leave the TV set. Instead, they began to worsen because, in trying to self-treat by watching TV less, he actually spent more time outdoors. Not until an exam with Dr. Stout in 2005, Vega’s first year in Kansas, did he learn that the sun — rather than TV — was the cause.

Now, of course, Vega wishes he could go back and wear sunglasses. He has a big pair that covers the entire area around his eyes, and he wears the lenses every time he leaves the house. Twenty years ago, they could have saved him two costly surgeries, years of eye pain and the current financial hardship for his family. But by now, for Vega, that knowledge came too late.

Doctors recommend people consider three main factors when buying sunglasses: the lenses, their intended use and the frame. So far, most of the country isn’t paying attention.