Nonprescription sunglasses are sunglasses with lenses that contain no power for the correction of refractive errors (nearsightedness, farsightedness or astigmatism) or presbyopia (age-related loss of focusing for reading and other close-up tasks.)
Another term sometimes used to describe this type of nonprescription eyewear is plano sunglasses.
Because they don’t require a prescription from an eye doctor, nonprescription sunglasses can be purchased from a wide variety of retailers–including eye care offices, optical shops, department stores, drugstores, discount stores (Walmart, Target, etc.), sporting goods stores and many, many websites.
And because they are available from so many sources and at such a wide range of prices, it’s good to learn as much as possible about nonprescription sunglasses to make sure you know exactly what you are getting and how well the lenses protect your eyes from the sun.
Why Nonprescription Sunglasses Are Important
Nonprescription sunglasses may be even more important than prescription sunglasses.
Why? Because most prescription eyeglass lenses–even if they are perfectly clear–provide some protection from the sun’s harmful ultraviolet (UV) rays. In fact, the lens materials used for most high-index eyeglass lenses automatically block 100 percent UV without the need for lens tints or coatings.
Many soft contact lenses also absorb a significant amount of the sun’s UV rays, preventing harmful radiation from penetrating the eye.
UV protection is important because too much exposure to ultraviolet radiation during childhood and early adulthood has been associated with increased risk of serious eye problems such as macular degeneration later in life.
In fact, the World Health Organization (WHO) has classified UV radiation as a potent carcinogen that can cause skin cancer by altering a person’s DNA. The organization also says the sun’s UV rays are directly or indirectly responsible for a significant percentage of cataracts.
People who have vision problems and require corrective lenses are automatically reducing their eyes’ UV exposure by wearing prescription eyeglasses or contact lenses. It’s people who don’t need prescription eyewear who are more at risk of UV damage to their eyes–unless they wear nonprescription sunglasses.
Contact Lenses–Some UV Protection, But Not Enough
While it’s true that some contact lenses block UV rays, contacts cannot provide complete UV protection for your eyes because they cover only a portion of the front surface of the eyeball.
In addition to increasing one’s risk for cataracts and macular degeneration, ultraviolet radiation also can cause damage to the exterior of the eye and to the delicate skin of the eyelids and facial tissue near the eyes.
Therefore, large, close-fitting nonprescription sunglasses should be considered essential gear for anyone wearing contact lenses–to supplement the UV protection the contacts may provide; to protect the eyelids and delicate skin around the eyes from cancer risk; and to shield the eyes from dust and drying winds that can cause contact lens discomfort.
Choosing The Right Lenses
In most cases, polycarbonate lenses are the best choice for nonprescription sunglasses. These lenses block 100 percent of the sun’s UV rays and are significantly lighter than regular glass or plastic lenses.
Also, polycarbonate lenses are 10 times more impact resistant than sunglass lenses made of other materials, making them an excellent choice if you plan to wear sunglasses for sports, carpentry, landscape work and other activities that pose an increased risk of eye injury.
Keep in mind that the color and density of the tint you choose for the lenses is a matter of personal preference– it has nothing to do with the amount of UV protection the lenses provide. (That’s controlled by the lens material or, in some cases, by an added UV-absorbing lens treatment.)
For superior protection from glare caused by light reflecting off water, vehicle windshields, roadways and other reflective surfaces, choose polarized lenses for your nonprescription sunglasses. You’ll pay extra for this feature, but the benefits of polarized lenses almost always are worth the extra cost.
Choosing The Right Frames
When you shop for nonprescription sunglasses, you have many, many styles to choose from. Whatever style you choose, make sure the frames fit properly:
- The edge of the frames should protrude slightly beyond your face so the temples of the frame don’t put pressure on the side of your head.
- Make sure the temples are long enough to be adjusted behind your ears for a secure fit. (Some styles have straight temples that don’t curve around the ear and instead rely on gentle pressure of the end of the temple against the back of your head for a secure fit.)
- Check the nosepiece for size and comfort. The frame should fit securely without pinching the bridge of your nose.
- While wearing the sunglasses, move your head up and down, and bend over (as if to pick up something up from the floor). If they’re fitting properly, the sunglasses should stay comfortably in place.
The color and style of the frame you choose is a matter of personal preference. But if you plan to wear nonprescription sunglasses for basketball or other active sports, choose an unbreakable, wraparound style frame designed for sports wear. These frames sometimes also have other safety features, like special cushioning on the bridge of the frame.
For the best UV protection possible, choose a close-fitting frame with wide temples to increase the shielding effect of the eyewear and decrease the amount of sunlight reaching your eyes from outside the diameter of the lenses.
How To Make Sure Lenses Block 100 Percent UV
It’s impossible to tell how well nonprescription sunglasses block the sun’s harmful UV rays by looking at them. UV protection is not determined by the color or darkness of the lenses.
Most nonprescription sunglasses that provide 100 percent UV protection will have a label or sticker on the lenses that says so.
To be certain about the level of UV protection your sunglasses provide, take them to a professional optician. Many optical shops have an automated instrument that can measure this for you.
Better still, to be sure you get the best optics, durability, fit and UV protection with nonprescription sunglasses (and resolution of any problems after the sale), purchase them from an eye care professional.
Article ©2013, Access Media Group LLC. Source: Nonprescription Sunglasses by AllAboutVision.com.