Ultraviolet radiation and myopia

I feel like writing another article about the possible benefits of something we’ve all heard is bad for us. Ultraviolet radiation (UV) sounds bad. Maybe because of the word radiation (not a bad word though) and then maybe all the news warning us about UV exposure. I’ve had many sunburns and believe it’s contributed to a couple of skin problems I’ve had so I believe the redness and pain associated with sunburns is a pretty obvious sign of too much sun. As a kid in the 70’s I remember putting zinc oxide on my nose. It was a thick bright white cream that definitely was noticeable. I wish I had a picture of that when I was sitting on the lifeguard stand watching all the other kids get their UV (and chlorine) exposure at the pool.

You’ve got to wonder though how our species ever survived with that constant stream of the suns rays just bearing down on us all the time. Scientists have divided up that UV band of radiation into 3 forms….A, B and C. A is the least harmful and C is the worst but C doesn’t even reach us because the atmosphere’s ozone absorbs that band. Why did we even call it UV-C if it doesn’t reach us? We can create UV-C ourselves through welding however. See the chart at the end showing the UV ranges.

One huge benefit of UV exposure is our body uses it to produce vitamin D. We can also get vitamin D from other sources and you’ll find plenty of foods supplemented with vitamin D. That just makes me wonder why all the news about vitamin D deficiency. I have read that too much UV-B exposure can actually destroy vitamin D production but that article I read didn’t say if that was 1% destroyed or 100%. That’s what bothers me about some of the information we get unless you dig further in the research. And this is where I think some organizations have gone too far with their warnings. They make the sun sound like it’s horrible! Too much of anything isn’t good for you but articles talking about avoiding UV just seem wrong. Life wouldn’t exist without it. Too much vitamin D supplementation isn’t good either….that’s toxic. Do they talk about that? Rarely. Instead of warnings, we should talk about moderation.

Here’s another thing I’ve been interested in regarding UV radiation. Most of the contact lenses I prescribe have an FDA approved UV blocking agent in the lenses. I don’t know when that all started. Since I don’t wear contact lenses and neither do most other people, will those that wear these UV filtering contact lenses be better off than the rest of us? And then there are glasses that have UV protecting effects. Will people that wear glasses be better off when the results of UV accumulation over a lifetime are more obvious regarding diseases attributed to UV exposure? I do wear sunglasses outside….sometimes. Most sunglasses, even cheap ones, block practically all UV radiation and our car windshields block that as well. I’d like to know how I can measure my lifetime UV exposure. Have I exceeded it? How can I possibly know if I have a little left over so I can go play outside?

But there’s one more thing that is interesting about the possible benefits of UV exposure…in children. It’s thought that the outdoors might provide some protective effects against myopia development. That means some very credible studies are finding the sun is good for kids. There’s even at least one study that shows that UV exposure may provide a certain protective effect against myopia. Instead of “protective” can I say benefit?

I say get outside and enjoy whatever weather you’ve got. Put down the ipads and back off the consoles and let me put up a permanent basketball goal at my house! The kids need to be outside more!

Here’s a study about UV and myopia.

http://www.ncbi.nlm.nih.gov/pubmed/22669720

 

UV graphic

UV graphic

 

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