Dr. Fellers demonstrates the importance of the proper sports eyewear at the Wente Vineyards Classic Professional bike race.
Each sport has its own unique visual demands both with regards to vision and eye protection. For cycling, I use a high wrap frame that sits higher on the bridge of my nose. This blocks both wind and excessive sun which can be detrimental when racing. When riding, you sit in a tucked position looking slightly upwards. For that reason, I want to make sure that sunglasses sit up slightly higher than a casual-wear frame would otherwise be positioned, and for prescription lenses the optical center of the lens should be set accordingly. Those who use a progressive lens prescription will be happy to hear learn that there are lenses designed exclusively for use on the bike, optimizing both distance and near viewing areas and minimizing peripheral distortions that can be dangerous when cycling.
Lens color is the next aspect to consider. Polarized lenses block glare off of flat surfaces and are ideal for cycling on tarmac. Polarization is no longer limited to grey and brown, but is now available in almost any shade. I still prefer grey polarized lenses for bright sunny days like we had this weekend in Livermore, Ca, but here in Santa Cruz, I often use a high-contrast/low-light lens for riding under the trees, in and out of shadows or in the fog. Yellow or rose are my two colors of choice for low-light lenses, although many cyclists also use green. These colors increase contrast without blocking as much light as a dark grey lens which generally blocks 90 to 95% of light across the visible spectrum. I also have a clear lens which I use for night races which I don't use often, but is perfect for specific events.
Lens material is the third item to choose in any sports lens. I exclusively ride in impact resistant materials such as trivex or polycarbonate. You never know when a rock will come hit your lens, and I need to know that I will be protected. Both materials also offer 100% ultraviolet protection.
Many frames such as the Smith Pivloc that I am wearing in the photos offer lens interchangability which allows me to choose the lens color that matches my ride for the day. Ultimately, having the right eyewear will enhance your experience and allow you to focus on the road.