Ok, Bikers, if you are looking for an economical photochromic sunglasses that you can wear in the day and night without having to change or pack extra glasses, then the Eclipse is a an excellent option for you. When exposed to UV rays or the sun, the Eclipse change from Clear to a Moderate Gray. For most bikers, the lenses are dark enough; and the satisfaction rate is quite high. We estimate at least 80% of the bikers who purchase the Eclipse are satisfied with the lenses. However, if you are more sensitive to bright sunlight, then we highly recommend the Eclipse XT. The Eclipse XT are built with genuine Transition XtrActive lenses, the darkest Transitions lenses on the planet.