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UV Photos Show the Areas We Miss When Applying Sunscreen

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Sunscreen only works if you're actually wearing it. And it's too easy to go through the motions of putting on sunscreen while still leaving large amounts of skin unprotected. Even if you're applying the recommended shot glass of sunscreen before you head out into the world, parts of your skin may still be exposed to harmful rays. Just check out these UV images taken by researchers at the University of Liverpool, spotted by the UK's Metro.

The black-and-white images were taken with a UV camera so that any part of the skin covered by UV-blocking sunscreen would appear dark. Skin without sunscreen on it, by contrast, remains visible. The 57 volunteers in the study—which was recently presented at the British Association of Dermatologists' Annual Conference—were instructed to apply sunscreen to their face as usual.

A black-and-white UV photo of a woman’s blotchy sunscreen application

Some volunteers were more thorough than others, but as a whole, the group ended up missing a median of 9.5 percent of their faces. Men with beards tended to miss a lot of their faces, you might notice in the photos, and people seemed to have trouble with covering the full area around their mouth. However, the main problems occurred around the eyes. Many people missed their eyelids, and more than three-quarters of the group missed the medial canthal region, or the area between the bridge of the nose and the inner corner of the eye.

A UV photo of a man shows white patches of bare skin underneath dark-looking sunscreen.

The finding is significant because the area around the eyes are particularly susceptible to skin cancer. According to the abstract presented at the conference, 5 to 10 percent of skin cancers occur on the eyelids.

Knowing this doesn't necessarily help, though. When the participants were brought back for a second visit, the researchers gave them new instructions that included data on cancer risks for eyelids, the results barely changed. People put slightly more sunscreen on around their eyelids (they missed a median 7.7 percent instead of 13.5 percent of the area) but almost everyone still missed their medial canthal area.

A woman turns her face to show sunscreen coverage in a UV image.

It's not a surprising finding, considering the fact that no one wants to get sunscreen in their eyes. Sunscreen manufacturers recommend that you keep it out of your eyes, and if it does run, you'll end up in tears. So it's not particularly useful to tell people they should be coating their eyelids in Coppertone.

To keep your face super smooth and reduce your likelihood of sun damage, then, the message is clear. Better get some shades, unless you've got a UV-blocking eyeshadow on hand. Better yet, get yourself a hat, too.

[h/t Metro]

All images by Kareem Hassanin, courtesy Kevin Hamill

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Big Questions
How Long Could a Person Survive With an Unlimited Supply of Water, But No Food at All?
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How long could a person survive if he had unlimited supply of water, but no food at all?

Richard Lee Fulgham:

I happen to know the answer because I have studied starvation, its course, and its utility in committing a painless suicide. (No, I’m not suicidal.)

A healthy human being can live approximately 45 to 65 days without food of any kind, so long as he or she keeps hydrated.

You could survive without any severe symptoms [for] about 30 to 35 days, but after that you would probably experience skin rashes, diarrhea, and of course substantial weight loss.

The body—as you must know—begins eating itself, beginning with adipose tissue (i.e. fat) and next the muscle tissue.

Google Mahatma Gandhi, who starved himself almost to death during 14 voluntary hunger strikes to bring attention to India’s independence movement.

Strangely, there is much evidence that starvation is a painless way to die. In fact, you experience a wonderful euphoria when the body realizes it is about to die. Whether this is a divine gift or merely secretions of the brain is not known.

Of course, the picture is not so pretty for all reports. Some victims of starvation have experienced extreme irritability, unbearably itchy skin rashes, unceasing diarrhea, painful swallowing, and edema.

In most cases, death comes when the organs begin to shut down after six to nine weeks. Usually the heart simply stops.

(Here is a detailed medical report of the longest known fast: 382 days.)

This post originally appeared on Quora. Click here to view.

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Medicine
Why Haven't We Cured Cancer Yet?
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Walkathons, fundraisers, and ribbon-shaped bumper stickers raise research dollars and boost spirits, but cancer—the dreaded disease that affects more than 14 million people and their families at any given time—still remains bereft of a cure.

Why? For starters, cancer isn't just one disease—it's more than 100 of them, with different causes. This makes it impossible to treat each one using a one-size-fits-all method. Secondly, scientists use lab-grown cell lines cultivated from human tumors to develop cancer therapies. Living masses are far more complex, so potential treatments that show promise in lab experiments often don't work on cancer patients. As for the tumors themselves, they're prone to tiny genetic mutations, so just one growth might contain multiple types of cancer cells, and even unique sub-clones of tumors. These distinct entities might not respond the same way, or at all, to the same drug.

These are just a few of the challenges that cancer researchers face—but the good news is that they're working to beat all of them, as this TED-Ed video explains below.

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