5 rules of healthy vision everyone should follow

Don’t think you need eye exams because you have 20/20 vision? Think again, says Lee.

“It’s like saying, ‘I don’t need to go to the dentist because my teeth are straight,’ ” she says. “Vision is only part of what we check during an eye exam.”

Your doctor will also examine your retina, optic nerve and eye pressure—all areas where you could have problems without any noticeable symptoms.

“We’re looking for the beginnings of eye conditions like macular degeneration, glaucoma and cataracts, which can be very serious and even trigger blindness if they’re not caught early,” Lee adds.

Dilation, too, is part of a yearly exam, and although it does have the annoying side effect of temporary blurry vision, it’s crucial nonetheless.

“When we dilate the eye, it opens the pupil and gives us a better view of the retina, lens and blood vessels in the back of the eye”—allowing your doc to catch what could be hidden problems, Lee explains.

It’s tempting to assume you should see an ophthalmologist (a medical doctor who goes to four years of medical school, followed by four years of residency) for routine checkups rather than an optometrist (who goes to optometry school for four years, and often does one year of residency). Yet both can perform eye exams, prescribe glasses and contact lenses, and treat eye diseases and prescribe medication.

Lee suggests thinking of an optometrist as your primary care eye doc who you see every year.

If you have eye issues, such as cataracts (which require surgery that only an MD can perform), macular degeneration (deterioration in the retina that causes blurred vision) or diabetic retinopathy (damage to the blood vessels in the retina due to high blood sugar levels), your optometrist will likely refer you to an ophthalmologist if surgical treatment is necessary. The two docs will then communicate with each other about your care.

“Oftentimes, patients with serious eye problems will see an optometrist once a year and an ophthalmologist six months later, so it’s even more likely that any changes in their eyes will be detected on the early side, which can help the prognosis,” Lee says.

Routine checkups are also a good way to learn about new innovations in eye care. For instance, last month, the U.S. Food and Drug Administration (FDA) cleared the first contact lens that automatically darkens when exposed to bright light. The Acuvue Oasys® with Transitions® Light Intelligent Technology™ leverages technology similar to the kind in glasses that darken in sunlight.

Learn more about Acuvue, including safety information.

If your eye doctor determines that you need glasses, contacts or both, you should know that the prescriptions can be different because eyeglasses are positioned a few inches from your eyes, whereas contact lenses sit directly on the surface.

Depending on the degree of your refractive error, which dictates whether you are nearsighted or farsighted, and whether or not you have an astigmatism (when the clear front cover of the eye called the cornea or the lens is irregularly shaped), the power specified on your contact lens Rx could be significantly different than what you see on your glasses prescription, explains Lee.

Note, too, that most contact lens prescriptions expire after a year, whereas most eyeglasses prescriptions expire after two years.

You’ll also notice additional measurements on your contact lens prescription, including your lens base curve (so that the lenses fit well on your corneas) and diameter, which is essentially the overall size of the lens, based on the size of your eye.

Buying contact lenses from a website has become increasingly common: A 2015 study by The Vision Council found that about 30% of contact lens wearers had purchased contacts online in the previous six months.

In general, buying contact lenses from e-retailers is safe, but whether you’re purchasing contacts or glasses online, raise an eyebrow if a digital seller doesn’t require a current Rx—it’s a red flag signaling that the company is taking shortcuts when it comes to eye health. Keep in mind, too, that buying contacts or glasses directly from your eye doctor or a brick-and-mortar store using a current, valid prescription is also a great choice.

“Opticians do an extensive fitting—they look at how the glasses sit on your face, and make sure the center of the lens is at the center of your pupil,” Lee says. “This can make a big difference, particularly if you have a high prescription, astigmatism or progressive lenses.”

The basics that can improve your overall health—eating right, being active, knowing your family history—can have an impact on healthy vision, too.

“Obesity and lack of physical exercise can increase your risk of developing diabetes, which can lead to diabetic retinopathy—a condition that can cause vision loss,” Lee explains.

What’s more, nutrients found in fruits, veggies and lean meats—like omega-3 fatty acids, lutein and vitamins C and E—have been shown to help ward off age-related vision problems, such as cataracts and macular degeneration.

It’s also important to know if anyone in your family has been diagnosed with an eye condition, since many of them are hereditary. “If your dad had glaucoma, for example,” Lee says, “it might prompt us to do additional testing or recommend that we see you more than once a year.”