If you spend any time at all on the water, you’ve probably noticed that everyone wears sunglasses. If you’re the observant type, you may have also noticed that a high percentage of those sunglasses have a chrome logo on the side that looks like the letter C or a stylized crashing wave. These are not those glasses.
Costa has a firmly entrenched position in the polarized sunglasses market here in Southwest Florida, and it’s really impossible to talk about any other brand without making a comparison to their products. Ono’s Eyewear makes their lenses from a plastic called CR-39, which is also used by some prescription lens makers. According to Wikipedia, CR-39 is transparent in the visible spectrum and is almost completely opaque in the ultraviolet range. It has high abrasion resistance, in fact the highest abrasion/scratch resistance of any uncoated optical plastic. CR-39 is about half the weight of glass with an index of refraction only slightly lower than that of crown glass, and its high Abbe number yields low chromatic aberration, altogether making it an advantageous material for eyeglasses and sunglasses. CR-39 is also resistant to most solvents and other chemicals, gamma radiation, aging, and to material fatigue.
You are currently not logged in
By logging in you can see the full story.