Sun Glasses

This is a guest post by  Michael Spanjol who is a Product Tester with ADS Sports Eyewear. His activities include golf and mountain biking.

Buying sunglasses for long day-time runs can be one of the most important and healthy investments you can make. Adults and children need protection from UV rays to prevent an array of health issues that arise from even short term ocular exposure to the sun. This issue is not fashion. The issue is function.

 

Health

Runners come in all ages, and we must consider the health benefits for everyone. Children and blue eyed adults are at the most risk for damage from UV rays. Children are more at risk because their eyes are more transparent at their young age and let a higher percentage of light through. Blue eyes are more transparent than dark eyes and are at more risk for this same reason. By reducing the amount of UV exposure you and your child receives you will also reduce their risk of developing conditions that can lead to blurred vision or even blindness. The most common conditions are:

1. Skin Cancer - 10% of skin cancers are found on the eyelid 
2. Cataracts - Clouded Vision. Eventual Blindness. 
3. Photokeratitis - Sunburn of the Eye. Temporary, but painful. 
4. Macular Degeneration - Damage to your finite number of light sensors. 
5. Pterygium - Negatively affecting abnormal growth on your eyeball.

So what can you do to curb these diseases? Wear sunglasses that offer 100% UV protection through the lenses while providing peripheral coverage that keeps sun rays from bouncing off of the inside of your lenses and into your eye.

 

Lens Materials

There are only two lens materials approved for use as sports lenses: Polycarbonate and Trivex. If you are purchasing glasses for active wear you need unbreakable lenses or you will be putting your eyes at great risk for injury.

Polycarbonate - Virtually Unbreakable. Available as a Tinted, Transitions, Clear, or Polarized lens.
Trivex - 3 times stronger than Polycarbonate. Also better optics than Polycarbonate.
SR-91 - Polarized Trivex. Also slightly better optics than standard Trivex.
CR-39 - Breakable plastic. Usually used as an insert behind Poly or Trivex lenses.

 

Lens Colors

Color	Light Condition	Description
Copper	Medium to Very Bright	Provides the most contrast and ability to recognize changes in road surfaces or textures. Also improves depth perception.
Grey	Medium to Very Bright	Maintains true color. More soothing to eyes because it seems darker. Ideal for people with sensitive eyes.
Yellow	Low Light	A light gathering color that tames the glare of oncoming headlights and makes the world look brighter.
Light Rose/Light Copper	Low Light or Dark	Provides contrast at night.

 

Polarization

Your current sunglasses may block 100% of UV rays but without polarization you will still experience glare that hinders and strains your eyes.

More Sun = More Glare = More Eye Strain, regardless of UV protection.

Doctors often prescribe temporary polarized lenses to patients who have had cataract surgery or Lasik to reduce light sensitivity from glare. Polarization also provides a better view of the world around you.

 

Prescriptions

Something exciting that has happened in the world of prescriptions for sport sunglasses is the development of Free-Form Digital lenses. The problem used to be that when you put a traditional style prescription into wrap or sport sunglasses, the prescription would become distorted once the lenses began to ‘wrap’ around your face. This created peripheral distortion known as the ‘fishbowl’ effect.

New Free-Form Digital Prescriptions calculate a prescription at every single point on the back of the lens, not just the focal center, effectively eliminating the ‘fishbowl effect’. These new prescription lenses can be made in any color, with or without polarization, and with or without transitions.

 

Final Thoughts

Clearly there is an abundance of information available for when the time comes to purchasing the right pair of running sunglasses. Your personal style or face shape will help decide which frame works best for you but when it comes to lenses you should be well informed on what you are buying. Sunglasses can save years for your eyes just like sun block lotion can save years for your skin.