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?
- 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?
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, lets others see your eyes better and eliminates the annoying white glare spots in photos taken with a flash.
- Find out about the hidden eye health dangers of UV
- About the LASIK experience: before, during and after laser eye surgery surgery
- Block harmful blue light with Zeiss DuraVision BlueProtect
- Save on eyewear with coverage that's accepted by thousands of eye doctors
I'm interested in the glasses that change to sunglasses when you go outside. Can you tell me more about them?
These are 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 most UV light.
To learn more about photochromic lenses and to compare the advantages of the major brands, please see our article on photochromics & tints.
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:
Men with larger faces can have a hard time finding a fashionable frame that fits. Here's one from the Chesterfield XL collection.
- Timex Max frames for men from Kenmark
- Chesterfield XL frames for men from Safilo
- A&A Optical XXL
- Fatheadz Eyewear (they also have sunglasses)
- 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 his or her place while reading
- Using a finger to follow along while reading
- 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.
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.
Try these interactive Rx forms to learn what the measurements mean on your eyeglass prescription or contact lens prescription.
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 recommended for children because it's very impact-resistant. Trivex is another very impact-resistant lens material that also works well for children's glasses.
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 eye care 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 a 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, in the form of either 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?
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; in that case 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?
-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, eye doctors generally write the letters DS or SPH after the first number to let the optician know that astigmatism wasn't overlooked.
The final number (180) is the direction of the astigmatism. Astigmatism, a football-shaped eye, can be measured in any direction around the clock. Numbers from 90 to 180 are used 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, certain numbers denoting the amount of near reading strength may be 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 February 2014]