Choosing the Right Sunglasses

Wearing sunglasses isn’t just a fashion statement but a personal decision to protect the eyes from unnecessary glare, destructive UV rays and intense light. A good shade should eliminate specific light frequencies that may blur vision. Sunglasses manufacturers use various technologies such as Tinting, Polarization, Photochromic lenses, Mirroring, Scratch-resistant coating, Anti-reflective coating, and UV Coating in order to abolish the usual problems with light.

Tinting:  The different colors of sunglass lens have been produced with certain goals in mind.  Here a few good things to know when choosing the right color of tint of your sunglasses:

Gray tints – distorts the least amount of color while reducing the brightness in totality. It’s a good choice for driving and general use.

Yellow or gold tints – are good in reducing blue haze, a kind of glare produced by blue light when it bounces off and scatters light. When this tint eliminates the blue light, it allows the other part of the light spectrum to pass, thus making the view bright and sharp. Yellow tint distorts color perception though. It’s a good choice for snow glasses.

Amber or brown tint – are also advisable for general usage. They reduce glare while absorbing higher frequency colors, especially blue light in addition to UV light. This is also a good protection from the early formation of cataracts. It provides better contrast and clarity but also distorts color like the yellow tint.

Green tints – are rather popular for offering the highest contrast and the most visual acuity than any other tint.

Purple and rose tints – are good for hunting or skiing because they offer the best contrast for objects when the background is either green or blue.

Aside from considering tints, you must also consider the kind of coating sunglasses may have. Here are the coatings that sunglasses manufacturers may add to their products and the purpose of each coating:

Ultraviolet Coating – A good ultraviolet coating should be able to block off UV-A and UV-B rays. Intense and prolonged exposure to UV light will tend to cause a  “sunburn” to the eyes. The sunglasses should indicate 100% protection from both kinds of UV light so that you can be safe from early development of cataracts or macular degeneration which are leading causes for blindness in people older than 65.

Anti-reflective coating – This helps in reducing the light that is reflected into the eyes coming from the back of the sunglass lens. When light hits the back of the lens of the sunglasses, it produces some kind of a “back-glare” and when it is bounced into the eyes, it becomes a problem. By utilizing a very hard thin film , which has an index refraction close to air and glass, reflections are produced which cancels off by destructive interferences and reduces the glare.

Scratch Resistant Coating – This is am important protection for the various coating applied to the surface of the sunglasses. Glasses may be scratch resistant but plastics are surely not.  It would be such a waste if your sunglasses have all the other kinds of coating but lack this.

Mirror coating – This kind of coating results to reflective sunglasses. It’s often referred to as half-silvered and it reflects about half of the light and lets half of the light that strikes its surface to pass through. This kind of shading can be categorized into two – the gradient or the bi-gradient. The gradient kind of coating change the shade from top to bottom and works to filter light from top and allows light from bottom or straight ahead. The bi-gradient protects from light coming from the top and bottom and allows the one that comes from straight ahead. This kind of coating is not protected by scratch resistant coating though. It usually is placed after the Scratch resistant coating is placed.

Lastly, but not the least to consider are the kinds of lens utilized in the sunglasses. Technology has brought us to be familiar with two terms - polarized and photochromic.

Polarized lens – This kind of lens reduces the glare coming from horizontal surfaces such as a body of water or the highway. Because most light will be coming in horizontally, the lens will only allow vertically light to pass through. Many glasses that claim to have polarized lenses are often fake and it’s important that you now how to test for the right one.  You must find a reflective surface like the hood of car. With you so-called polarized sunglasses on, tilt your head slowly from left to right or vice versa. The glare should increase or decrease as you adjust your angle of view. If it does not, it’s not polarized.

Photochromic - It’s also known as photochromatic lens. This kinds of lens have silver chloride or silver halide embedded in them and a certain reaction occurs when it react wit UV light. Thus, sunglasses with this kind of lens darken when exposed to the sun or UV light source.

Hopefully, now that you are equipped with more knowledge, you can make better choice next time you buy your sunglasses.