Eyeglasses:
Frequently Asked Questions

Why should I bother to go to the eye doctor when I can simply pick up an inexpensive pair of eyeglasses at the store?

Some people do have good luck with drugstore reading glasses. However, you need to visit your eyecare practitioner regularly for two reasons:

• Regular eye exams are the only way to catch "silent" diseases in their early stages, when they're more easily treated.
• One-size-fits-all reading glasses do not work well for people who have a different prescription in each eye, or whose eyes are not centered in the lens. Headaches are a common problem in those cases.

What's the secret to getting eyeglasses that look great on me?

First, decide which of the seven basic face shapes you have and read the accompanying tips about frames that go well with your shape. Then, find out which colors suit your skin, eye and hair colors.

How do I avoid annoying reflections on my eyeglasses?

Anti-reflective coating, also known as AR coating, helps you to see through your eyeglasses more easily, allows others to see your eyes better and eliminates the annoying white glare spots in photos taken with a flash.

Read more about anti-reflective coating.

I'm interested in the glasses that change to sunglasses when you go outside. Can you tell me more about them?

These lenses are known as photochromic lenses. When they're exposed to ultraviolet light, they become darker or change to a different color. Most brands remain pretty light when you're driving, because windshields block UV light.

To learn more about photochromic lenses, and compare the advantages of the major brands, please see our Photochromics & Tints article.

I find most eyeglasses to be too small for my head. Do you know of any brands that carry larger frames?

These days, most eyewear lines include at least one or two frames in larger-than-average sizes. But you might try styles from these collections, which have several larger styles for wider faces and/or people who need longer temple pieces:

• Cazal frames from Eastern States & Ultra Palm Eyewear
• Columbia Sportswear frames from L'Amy Group
• Prada frames from Luxottica Group
• Rodenstock frames
• Hart Schaffner Marx frames from Signature Eyewear
• Silhouette frames
• Harley-Davidson frames from Viva International Group
• Stetson, John Deere, Sophia Loren, and Gloria Vanderbilt frames from Zyloware

What are the warning signs that a child might need glasses?

• Consistently sitting too close to the TV or holding a book too close
• Losing her place while reading
• Using a finger to follow along while reading
• Squinting
• Tilting the head to see better
• Frequent eye rubbing
• Sensitivity to light
• Excessive tearing
• Closing one eye to read, watch TV or see better
• Avoiding activities that require near vision, such as reading or homework, or distance vision, such as participating in sports or other recreational activities
• Complaining of headaches or tired eyes
• Receiving lower grades than usual

Schedule an appointment with your eye doctor if your child exhibits any of these signs.

[Read more about eye exams for children and vision problems of schoolchildren.]

How do I choose glasses that my child will actually wear without breaking the bank?

The most important factor in getting a child to wear glasses is to let him or her help pick them out. Read more motivational tips.

Before you go shopping, check out our primer on Kids' Frames, which includes the top five trends in children's glasses. Also, learn what features make kids' glasses more durable (so you get more for your dollar) in our 10 Tips for Buying Kids' Eyewear article.

I'm worried that my son's glasses could break while he's wearing them. What's the best way to protect his eyes?

Polycarbonate is usually recommended for children because it's very impact-resistant. Read more about polycarbonate.

How can I prolong the life of my eyeglasses?

• If you're buying just one pair of glasses, avoid trendy frames that could go out of style quickly.
• If you're buying glasses for a child whose prescription changes often, ask to have new lenses put in the old frames, rather than buying new frames each time.
• Choose a style with spring hinges, which allow the temples to flex slightly outward without breaking the eyeglasses.
• Ask for scratch-resistant coating.
• Follow your eyecare professional's instructions for the proper care of your glasses. Improper care is a primary cause of damage to anti-reflective coating and can cause other problems as well.

How often should I get a new pair of glasses?

You should get a new pair if your prescription has changed; your doctor will let you know. Therefore, it's important to know how often to visit the eye doctor: it depends on many factors, but as a general rule, you should go once a year or once every two years. Your doctor can tell you what schedule is right for you.

If your prescription doesn't change very often, or at all, just get new glasses when you're tired of your old ones or they go out of style.

I can see fine to read or drive, but I'm having trouble with certain tasks, especially at work. What's wrong?

You should see your eye doctor if you're having any sort of problem with your vision. However, we can tell you some reasons this might be happening.

This is common problem for computer users who wear bifocals (which correct near and far vision) or reading glasses (which correct near vision), because computer monitors tend to be in your intermediate vision, neither near nor far. The solution is to ask your eye doctor about intermediate vision correction, either in the form of computer glasses, progressive lenses or trifocals.

Sometimes, the problem is that the near-vision portion of your glasses is not compatible with what you're doing. Golfers, for example, benefit from having that portion placed very low and in the inside corner, so that it doesn't interfere with their game. Read more about these special types of multifocals, called occupational lenses.

I'm tired of my "Coke-bottle" lenses. Is there anything I can do?

You could ask your eye doctor about high-index lenses, which are compressed, or aspheric lenses, which have a flatter curve than regular lenses. Read more about high-index and aspheric lenses.

The anti-reflective coating on my glasses is smeary (or foggy). What causes that, and what can I do about it?

Cleaning your eyeglasses improperly is a common cause of problems with anti-reflective coating. When you bought your eyeglasses, your eye doctor probably explained the best way to care for them; usually, you use lens spray and a certain type of cloth, like microfiber.

Sometimes, your eye doctor may be able to remove the damaged coating, but usually not. There's nothing you can do at home.

Do my glasses protect my eyes from the sun?

That depends. Many people have plastic lenses, which do not protect your eyes; you need to have UV coating for protection. Polycarbonate lenses have built-in UV protection. Glass lenses protect your eyes from harmful UVB rays, but not from UVA; some experts think UVA rays might have long-term, damaging effects on your eyes and skin.

What do all those numbers in my prescription mean?

An eyeglass prescription is written in a standardized format with standardized notation so it can be interpreted worldwide. Let's look at one and break it down:

-2.00 -1.00 x 180. The first number (-2.00) tells us the spherical refractive error (farsightedness or nearsightedness). In this case, because there is a minus sign in front of the 2.00, this patient is nearsighted. A plus sign would indicate farsightedness.

The second number (-1.00) is the astigmatism. If there is no astigmatism, we generally write the letters DS or SPH after the first number to let the optician know that we didn't just forget to write in the astigmatism.

The final number (180) is the direction of the astigmatism. Astigmatism, a football-shaped eye, can be measured in any direction around the clock. We use the numbers from 90 to 180 to indicate the orientation of the football shape.

There may be additional numbers in a glasses prescription. For instance, if the basic prescription is followed by a small number with a superscript (1^) it indicates prism correction. There may be more than one set of prism numbers for each eye.

Lastly, there can also be numbers denoting the amount of near reading strength needed (bifocal or progressive). They usually go from +0.75 to +3.00, depending on age and visual need.

The letters OD and OS in front of a prescription let us know which eye each string of numbers is for. OD stands for right eye and OS for left eye, while OU means both eyes.

[Page updated September 2006]