Well, the blue light produced by LED lights (your Christmas tree lights will likely be LED unless they are old ones you’ve had for ages) has been linked to eye problems.
One study warned that long-term exposure to LED lights can speed up the ageing of the retina, the delicate light-sensitive layer at the back of your eyes.
The French government scientists behind the report said this could raise the risk of age-related macular degeneration – that’s when the middle part of your vision becomes blurry.
But before you ditch your fairy lights, it’s worth noting that by long-term, the researchers meant several years – that’s a lot of looking at your tree! And overall, there just isn’t enough evidence to recommend against LED lights.
If you find that your Christmas tree lights are hurting your eyes though, you could try dimmable versions, to see if they are kinder to your eyes. Or swap lights that flash and flicker for ones that give off a steady glow.