Interesting discussion, with some items you need to know, and some items that no one knows yet.
First, this discussion focuses on the eyes. There is a “blue light therapy” for treatment of skin conditions and skin cancer prevention. That’s a different topic, for another post.
- Blue light is in the lower wavelength of colors that are visible to the human eye. The wavelength falls between 400 and 500 nanometers (nm).
- Blue light is generated by LED screens — computers, cellphones, tablets, televisions and game consoles.
- Researchers believe that peak damage to the eye can occur at wavelengths around 440 nm.
- Blue light also has the ability to disrupt sleep patterns at night, leading some researchers to discourage the use of electronic devices in the hour before bed.
What’s not known:
- How intense does the light have to be to cause damage?
- How long does the exposure have to be?
Some writers maintain that a low level of light over a long period can cause damage, but this is unproven.
What you could do:
Obviously, one could limit time in front of a screen and commit to not using a device between one and two hours before bedtime each night. However, with a lot of jobs, that’s simply not an option. And breaking the habit of texting before bed? Good luck with that!
Manufacturers have responded by developing special eyeglass lens coatings that filter blue light. Do they help? Frankly, the research to date is inconclusive. We don’t know if they help, but we see no obvious way in which they could harm the user either. The Scottish verdict of Unproven applies.
These blue light glasses are different from “computer glasses.” The latter are bifocal, trifocal or progressive lenses that reverse the sequence of the fields, so that the section used for reading is in the middle of the lens.
If you can afford them, you might want to try and see how your eyes feel after a week or two.