Here’s something you probably didn’t need to be told but will be happy to hear science confirms: fluorescent lights are bad for you.

A study from Swiss neuroscientist Mirjam Muench found that natural light made people more alert during the day and sleepier at night. This is a one-two punch: Fluorescent lights don’t just make the day drag on, they have you feeling wired at night. There’s a lot of attention paid to the impact of screen time on your sleep, but the culprit here is the same. Modern screens are basically just fluorescent lights in front of your face instead of over your head.

The damage done by fluorescent lights isn’t limited to tossing and turning, either. Nighttime exposure to fluorescent light correlates strongly with breast cancer, obesity and depression.

The Science of Circadian Rhythms

The main culprit might be related to circadian rhythms. Scientists haven’t understood much about the natural rhythms of sleep until lately, other than that they exist. New research, however, sheds light (pun maybe a little intended) on circadian rhythms. Your retinas possess specialized cells for sensing light—not colors, not shapes, but simply whether or not there is any light. These cells possess special sensitivity to blue light, and that’s mostly what fluorescent lights are emitting. That’s why when you look at your phone in the middle of the night just to check the time, you’re absolutely wired afterward.

Disrupting the circadian rhythms can lead to dramatic changes in the body overall. Other issues associated with disruption of circadian rhythms include immune system dysregulation, cardiovascular dysfunction, reproductive problems, mood disorders and learning deficits. Whew.

You Need Natural Light for Optimum Health

So those fluorescent lights will keep you perky and alert all day, right? Wrong. In fact, they’re more likely to make you feel worn out and frayed around the edges as anyone who has ever worked in an office knows. The Muench study found that what you need to stay alert is light, natural light, and as much of it as you can get. Not only will natural light make you more alert during the day, it will also help you to sleep more soundly at night. That’s the one-two punch of fluorescents in reverse.

Then there’s the small matter of light-related headaches. While the science is inconclusive, many doctors agree that, at the very least, fluorescent lights can trigger headaches in people otherwise predisposed to having them. The science connecting headaches with more old-school fluorescent bulbs is more conclusive: Yes, Virginia, that flicker really is causing your splitting migraine. Fluorescent lightbulbs might also cause your headache thanks to the ultraviolet radiation they give off; another reason they’re not terribly healthy to be around.

A Coming Revolution in Indoor Lighting?

New office lights are coming down the pike allowing for adjustments at previously unimaginable levels of detail. Chances are good, however, that unless you have a very tech-forward employer, you’re probably not going to see these in your office any time soon. Until then, turn off any fluorescent lights under your control where possible and bask in sunlight instead—and maybe consider a little CBD oil at night to help you drift off and stay asleep.