The more years of schooling you have, the higher your risk for nearsightedness.

Observational studies have suggested a link between education and myopia. But a new study used a genetic technique called Mendelian randomization to minimize the effect of several variables and provide stronger evidence of cause and effect.

Using eye examinations and questionnaires on education level, researchers used publicly available genetic data on 67,798 men and women in England, Scotland and Wales. They examined the many specific genetic variants linked to myopia and to the genetic predisposition to time spent in school, including higher IQ and other factors.

The researchers found that although genetic predisposition was a more powerful predictor of nearsightedness, years of education were strongly and causally linked to the condition. They acknowledge that the people in their database were generally healthier than the general population, which could lead to bias. The report is in the medical journal BMJ.

The lead author, Dr. Denize Atan, a consultant senior lecturer in ophthalmology at the University of Bristol, said the mechanism is unknown but may have something to do with reduced exposure to natural daylight.

“Clues from other studies suggest that children who spend more time outside are protected from the onset and progression of myopia,” she said. “One recent study found that just 11 hours a week of daylight exposure seemed to be enough to slow onset and progression.”

— New York Times

TAKING THE ITCH OUT OF MOSQUITO BITES

They are a common summer nuisance. Mosquitoes are pesky parasites leaving bite marks that can be unbearable to itch. So what’s the best way to stop yourself from scratching?

Jason Howland has the answer from a Mayo Clinic expert.

There are millions of mosquitoes swarming this summer, sucking blood and leaving itchy, red bumps on the skin.

“Their saliva deposits in the skin from where the bite is, and it’s causing a reaction to that saliva,” says Dr. Summer Allen, a Mayo Clinic family physician.

Allen says some of the tried-and-true home remedies for treating mosquito bites work well. Calamine lotion, over-the-counter hydrocortisone cream and even a cold compress can ease the itch.

“It’s going to sooth and kind of calm down that intense burning and inflammation that they’re feeling in their skin,” says Allen.

And, while it’s not always easy, it’s important to keep the itching to a minimum.

“If they scratch it hard enough, or depending on what they use to scratch their skin, they can cause a break in their skin,” says Allen. “They can develop a bacterial infection.”

Although using insect repellent and other prevention tips can reduce your chances of being bit, really, getting at least one skeeter bite this summer is almost inevitable.

“Time takes care of it, and try to do your best not to scratch it if you can,” says Allen.

— Mayo Clinic News Network