We have all heard about the dangers of UV light. Well there is so much more to know about UV. UVA is linked to cataract formation. I bet you didn’t know that. UVB is what causes sunburns, melanomas and is also a cause for pinguecula, pterigium and photokerititis. I know those words don’t ring a bell at all but have you seen those lumps and bumps on the inside white portion of your eye between your pupil and your nose? Those are what I’m referring to.
Sunglasses are wonderful to protect the eyes from UV if you know what to look for. First just having a dark lens is not enough. It must have a UV filter as well. It needs to block out the UV to 400nm, be large enough to provide coverage, and be consistent all the way across the lens. You may also want to consider poloroid as that really blocks out a lot more of the damaging rays.
Darker lens colors don’t necessarily mean better sun protection as the UV protection added to lenses is clear so even clear, gray, green, brown, yellow or rose lenses can offer adequate UV protection. More expensive lenses don’t always offer more protection. Also sunglasses are not just for sunny days. Up to 80% of UV rays can penetrate the clouds. So even on overcast days we should be wearing sunglasses.
You ask where does all this blue light come from? Well it’s essentially everywhere. It comes from the Sun but also from digital screens (TV’s computers, laptops, smart phones and tablets? Electronic devices and even fluorescent and LED lighting.
Blue light emitted from digital devices and computer screens is minimal when compared to the sun, BUT the amount of time we spend on these devices and computers AND the proximity to our face is where the risk lies. Also consider the cumulative effect over a lifetime. With children starting on these devices at very early ages this is becoming a larger and larger concern. UV damage is cumulative. 25-50% of UV exposure occurs prior to age 18. Children are more susceptiblee to retinal damage from UV because of a clear internal lens.
Consider one hour outside on a normal overcast day exposes our eyes to 30 times more blue light than spending one hour inside sitting in front of a screen.
This is just the first part of a two part blog post. The rest of the story tomorrow. It’s not all bad.