Naked Science Forum

Life Sciences => Physiology & Medicine => Topic started by: katieHaylor on 21/09/2018 09:34:37

Title: Is blue light bad for our eyes?
Post by: katieHaylor on 21/09/2018 09:34:37
Rachel says:

I've seen in the news about the possibility of blue light causing macular degeneration in the eye. Will my contact lenses that have UV protection in them protect against the blue light too?

I have also heard of skin care companies claiming that blue light causes damage to the skin- how true is this claim?

Can you help?
Title: Re: Is blue light bad for our eyes?
Post by: alancalverd on 21/09/2018 23:45:44
There are established safety levels for exposure to intense blue light. Early symptom of damage is temporary color blindness which may become permanent. We use spectrophotometry and a published "action spectrum" to design and test high-brightness workshops, operating theaters and cockpits - the noon sky above cloud is not always a safe workplace!

Blue light has some actinic effect on skin and is used to treat acne and neonatal jaundice, but most of the "science" put out by cosmetic companies is carefully worded bullshit.

UV-protective lenses will not absorb actinic blue light unless thay are visibly tinted.
Title: Re: Is blue light bad for our eyes?
Post by: evan_au on 22/09/2018 02:22:00
Quote from: Rachel
blue light causes damage to the skin
If the blue light is from an arc welder, then it will definitely harm both exposed skin and eyes.
- That's why welders use masks that are so dark that you can use them to look at the Sun during an eclipse.
- But normal exposure to blue light - the sky viewed from ground level, or blue-painted walls is not a risk.
- Some smartphones and computers simulate a dawn/dusk effect, where the amount of blue light in your screen is turned down at night, to help you sleep.

In the past, some "health" salons advocated ultra-violet sun-tanning beds. I think everyone now realises that extended exposure to UV damages skin and promotes cancer. But a small amount of UV every day helps vitamin D levels.