UV protection to 400nm seems to have been the standard for sun protection for a long time. More recently, maybe 12-13 years ago HEV protection became available in some sunglasses on the market but there hasn't been a new standard. HEV light, from my understanding is light in the 400-500ish wavelength range. A quick google search for sunglasses that protect against HEV light turns up some results that seem misleading. Here's an example from Oakley:
Harmful blue light rays are known as High Energy Visible (HEV) wavelengths. HEV light has been linked to several forms of eye damage. That’s why our Plutonite® lens material is engineered to block 100% of all harmful blue light up to 400 nanometers. In addition to protection, this is a performance benefit because blue light rays are a major factor in glare
If HEV light starts at 400nm then why are sunglass lenses that protect to 400nm claiming to block HEV light?
I would probably answer this question like this: Because Money.
Do you think these are misleading and potentially harmful claims?
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