A little more than a year ago, my eye doctor prescribed new disposable contact lenses. My insurance, he explained, would pay for only one six-month supply per year.

“I'll just take six months' worth then,” I told him.

Last week, I called to reorder. Since it's been more than a year, my insurance will pay for my next “6-month” supply, which I hope will last me a year or so.

You see, a few years ago, I got some advice from Keith Baratz, M.D., an associate professor of ophthalmology at the Mayo Clinic. If a contact lens is approved for continuous day and night wear for 2 weeks, he said, it can last twice as long if you wear it only during the day. (Read The Truth about Calories to discover even more need-to-know health and nutrition advice.)

When it comes to staying healthy, much of what we accept as gospel is actually heresy. But some of it is completely unnecessary. Here are 8 more items you can cross off your to-do list.

See your dentist twice a year

This advice originally came from an old toothpaste ad. There was no science behind it, and there still isn't. A 2003 review looked at 29 studies and found no conclusive evidence supporting a need to go every 6 months. If your choppers (and gums!) are healthy, once a year is enough to catch any developing problems, says James Bader, a research professor at the University of North Carolina school of dentistry.

Just don't wait longer than that: A study presented at the American Heart Association meeting last year found that having your teeth cleaned by a professional once a year lowers your risk of heart attack by 24 percent and stroke by 13 percent.

Don't eat after 8 PM

Calories can't tell time. There's no difference between the 6:30 a.m. and 8:20 p.m. kinds, says Susan Bowerman, assistant director of the UCLA Center for Human Nutrition. Plus, hitting the sack hungry can disrupt sleep patterns. In fact, new research suggests you should eat right before bed if you exercise at night, or if you're over 60. A protein-packed meal-or even a whey protein shake-provides more fuel for your body to synthesize muscle. (To add more flavor and nutrition to your drink, find out how to make the perfect shake.) It also helps combat the effects of age-related muscle loss.

How much protein? A recent study in the American Journal of Physiology found that elderly men who ate 35 grams of whey protein experienced more muscle growth than those who ate 10 or 20 grams.

Go for an annual full-body scan

They're pretty useless, particularly for the abdomen and pelvis, says Dr. Jonathan Goldin, a radiologist at UCLA. Often, scans miss lesions, giving a false sense of security-or they "find" something that's not there, leading to unnecessary anxiety and more tests. Scans can help detect lung cancer and coronary-artery calcium, but these tests are recommended only for people over 45 who have risk factors like smoking, moderately high blood pressure, or moderately high cholesterol. If that isn't you, you don't need a scan.

Throw away milk when it reaches the expiration date

The date on the carton is just the date after which it can't be sold. The milk probably has another week of freshness, says Bowerman. Give it a sniff and proceed. And if you drink sour milk, there'll be a flavor problem-oh, yes indeed-but you don't need to have your stomach pumped. There's another word for curdled milk: cheese.

Feed a cold

There's no science behind this old adage, says Dr. Jack M. Gwaltney Jr., head of the division of epidemiology and virology at the University of Virginia. "In the short term, what you eat doesn't matter at all," he says. "Drink lots of fluids, but eat whatever you feel like." That said, the cysteine in chicken soup has been proven to relieve mucus buildup and sore throat.

Starve a fever

Wrong again. A high temperature boosts your metabolism, causing you to burn calories. If you're weakened, the illness will hang around longer. So try to replace calories any way you can, says Dr. Ben Ansell, director of the Comprehensive Health Program at UCLA. "It's even more important to maintain regular fluid intake, as your body's demands may be at least twice what they are in other circumstances." Your fever could be caused by any number of ailments, so monitor it and see a doctor if it gets to 105 degrees or lasts for several days. Steer clear of colds and flu by avoiding the 6 Germiest Places You Touch Every Day.

Use a hard toothbrush to clean your teeth better

A soft one cleans just as well and causes less damage to teeth and gums, says Philip Mendelovitz, an associate professor of dentistry at the UCLA school of medicine.

Brush and floss twice a day

In terms of dental health, once a day is fine. "Plaque takes 24 hours to harden," Mendelovitz says. "One really good brushing every 24 hours is better than two half-baked attempts." But commit to the job-spend at least 2 minutes. And do it before bed. Saliva combats plaque, and its production decreases when you sleep, Bader says. But remember: This is just about plaque. Your breath is still going to reek in the morning, so be a good coworker/friend/close talker and either brush or use mouthwash when you wake up. 

Another reason to floss every day: New York University researchers found that people who floss infrequently are three times more likely to develop stomach cancer. Jot down a plan of when, where, and how you'll floss each day and you'll be more likely to actually do it, a German study found. Another great way to keep your teeth clean and healthy: Avoid these 12 Foods Your Dentist Would Never Eat!