This has got to be one of the all-time most frequently asked questions I receive. There seems to be a fair amount of confusion regarding the correlation between lens darkness and eye protection. Many people assume that the darker the lenses of their sunglasses, the better the eye protection. But is it true? In a word, no.
The darkness of your sunglass lenses basically has nothing to do with the degree to which they can be expected to protect your eyes. Really the only true benefit of dark lenses is that they can help alleviate discomfort for folks who have a high degree of sensitivity to bright light. So if you have sensitive eyes and you plan to go skiing or swimming, dark lenses will help to reduce your discomfort. But they will not necessarily protect your eyes any better than other lens colors.
For true eye protection, you will need sunglasses with lenses offering UVA and UVB protection (UV400), like all of our Matrix sunglasses. This type of protection filters out the harmful rays of the sun to prevent optical damage. Sunglasses with UV400 protection are labeled as such, so when you are ready to buy just read the product specifications.
You might also want to invest in a pair of sunglasses with polarized lenses, which help to filter the glare emanating from horizontal reflective surfaces such as roads or oceans. Polarized shades are usually labeled as such. When in doubt, you can determine polarity by holding the sunglasses up to a reflective window or computer monitor, with the sunglasses between you and the reflective surface. Look through one of the lenses at the reflection, and then rotate the sunglasses about 90 degrees. If the lenses are polarized, the reflective image will fade as the sunglasses are rotated in this manner.
So there you have it. In summary, to protect your eyes, forget about the lens color or darkness as these attributes have nothing to do with it. Instead, buy sunglasses with UV400 protection, and possibly polarized lenses as well.