It's hard enough to choose from the many frame style options, but you're also faced with picking out lenses. Lenses come in several tints and colors, and can be polarized if preferred. Do you know the advantages and disadvantages of polarized lenses?
What are polarized lenses?Sunlight can be absorbed or reflected in several different directions. Sunlight that is bouncing off horizontal surfaces such as water, land or the hood of a car is usually reflected back in a similar horizontal direction. This reflection produces an agitating source of glare that cannot only create visual discomfort but can also cause a potentially blinding glare. Glare has the potential to create a very dangerous situation, especially while driving. Polarized lenses contain a laminated filter that allows only vertically oriented light to pass through. This blocks the horizontally oriented light so glare is almost eliminated.
The most common colors of polarized lenses are gray and brown. However, depending on the manufacturer, many other colors may be available.
What are some advantages of polarized lenses?A high quality pair of sunglasses will usually include polarized lenses. A polarized lens offers the following advantages over non-polarized lenses:
- Improves visual comfort
- Improves contrast and visual clarity
- Reduces eyestrain
- Allows for true perception of colors
- Reduces reflections and eliminates glare
Do you need polarized lenses?Originally, polarized lenses were mainly worn by boaters and fishermen. Because a polarized lens reduces glare, it makes it much easier to see deeper into the water for viewing fish and other obstacles. Today, however, polarized lenses are enjoyed by the general public and offered in many popular sunglasses brands. Polarized lenses are beneficial for people who do a lot of driving and are also a great option for sports enthusiasts.
What are the disadvantages of polarized lenses?Polarized lenses can be troubling for people who need to see LCD (liquid crystal displays) screens clearly. In fact, wearing polarized lenses can make an LCD screen difficult to read and can even make it seem to disappear completely at certain angles. Therefore, operators of heavy equipment or pilots should not wear polarized lenses. Although polarized lenses are generally recommended for snow skiers, some downhill skiers complain that they do not provide enough contrast to differentiate between patches of ice, snow and hills, presenting a danger to the skier.
What are the alternatives to having polarized lenses?Most sunglasses lenses are simply tinted with a single color. Some high-quality sunglasses manufacturers provide different tinted lenses that are often made of polycarbonate or high quality glass and are very appealing to some wearers, even more than polarized lenses. The drawback to plain tinted lenses is that although they reduce brightness, they do not remove glare as a polarized lens does. Also, depending on the color, certain tints can impact how you perceive and differentiate colors. Some researchers question the fact that a tinted lens will allow the pupil to dilate, which may provide visual comfort, but can actually allow more UV radiation to enter your eye if the lens does not have built-in UV protection.
Polarized lenses and UV protectionMost high quality polarized sunglasses lenses offer UV protection. However, it is wrong to assume that just because a lens is polarized that it will also protect against UV radiation from the sun. You should always verify by the label or the seller of the product that the lenses protect against UV sun rays. Many polarized lens products are made of an impact-resistant material called polycarbonate, which contains UV protection.
Additional sunglasses lens optionsIf you are shopping for a pair of sunglasses, the following options may also appeal to you:
- Gradient tints: A gradient tint has a fully dark tint at the top of a lens and gradually fades to almost clear at the bottom of the lens. Double gradient tints are dark on top, become clear, and darken again. A double gradient tint will act to block light from both above and below.
- Mirror coatings: A mirror coating reflects light away from the wearer. As its name implies, it looks a lot like a silver mirror. A mirror coating can be combined with a tint, making it a great alternative to a polarized lens. The wearer cannot see the mirror, as it is only visible to others. Mirror coatings are also a popular add-on as a fashion statement. The mirror coating acts as a one-way mirror preventing others from making eye contact with you.
- Photochromic lenses: Photochromic lenses darken and change color whenever the wearer goes out into the sunlight. The tint is activated by UV light. When the wearer goes back indoors, the lenses slowly revert back to clear. Although photochromic lenses are quite versatile, they do not get as dark as a pair of sunglasses while driving. Car windshields do not allow enough UV light to enter in order to fully darken the lens.
White, Debra. The Handbook of Sunwear, Sponsored by the Sun Vision Alliance. "Sun Lens Options 101", pages 4-6.