Everything Surfers Need to Know About
Blue Light and Blue Blocking Surf Sunglasses
UV Radiation Does Not Reach the Retina and Cannot Harm It
Visible light spectrum.  The blue light is the blue on the left!
The sun emits a spectrum of electromagnetic radiation.  Some of the radiation is not powerful, and some is very powerful.  Fortunately the most powerful radiation (UV radiation) is blocked largely  the atmosphere.  Visible light is near the more powerful end of the radiation spectrum that is able to pass to earth's surface.
The most powerful electromagnetic radiation that reaches the retina is blue light.  Blue light waves are 400 – 500 nm in wave length and are (obviously) recognized by our eye as the color blue.  So when you see the blue ocean and the blue sky, you are getting hammered by blue light.  Light waves this short also scatter more easily than colors at the other end of the spectrum  That is why blue things (like the ocean) are more likely to cause glare.
What Can Surfers do to Protect Their Eyes:  Blue Blocking Surf Sunglasses.
  Even if your surf sunglasses offer 100% UV protection, they likely do not block blue light.  For a lens to block blue light in must have a yellow tint.  The lenses final color can range from yellow to dark amber.  The yellow tint does not necessarily reduce total light intake or make things appear darker.   They change the color of blue and green objects, but they do not change the other colors.  They will also reduce glare and improve color contrast.

The Spex, Tierra del Fuego and Mauricio all come with yellow tinted lenses that block blue light.
Most of the UV radiation that does enter to Earth's surface is blocked by the cornea.  One last bit of the least powerful UV radiation is absorbed by the lens, but no ultra violet radiation hits the retina at the back of the eye; only visible light is allowed to reach this fragile retina.   
What is Blue Light and Why is it Harmful to the Eyes?
Blue light is more harmful to people who have recently had cataract surgery.
In laboratory studies blue light has been shown to do damage to retinal tissue.  Several studies have been done and many doctors and research believe that blue light is a contributing factor to macular degeneration.  Some studies also say that total pigment and eye color are also important.  If your skin burns easily and you have light colored eyes blue light may be more harmful to you. 
Visible light spectrum.  The blue light is the blue on the left!
More Powerful Blue Light
Less Powerful Red Light
UV light lives over here
Blue blocking surf sunglasses
These blue surf sunglasses come with yellow lenses that block blue light.
Surf sunglasses without a yellow tint do not protect against blue light
Notice how the ocean is blue?  That is blue light in action!  But her surf sunglasses do not have a yellow tint - they do not protect her  against blue light.
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