Mom always warned you to turn a light on.
Maybe you were the kind of kid to stay up hours after your bedtime and read Nancy Drew under the covers. Or maybe as an adult you like to read before bed but don’t want to bother your partner by flipping on the bright bedside lamp.
Either way, you can still hear your mother’s oft-repeated warning in your head: “What are you doing reading in the dark? You’re going to ruin your eyes if you keep doing that.” So ... was Mom right?
Luckily, researchers have looked into the issue and come to a confident consensus: nope. Although reading in dark lighting is more difficult, it doesn’t damage your vision, according to the American Academy of Ophthalmology. (Learn how the eyes actually work here.)
This stubborn myth about the dangers of reading in the dark likely originated because most people experience some degree of eye strain when they read without proper lighting. Trying to read small words from a poorly lit page can make it difficult to focus, force you to squint, and possibly lead to dry eyes because you’re blinking less often, according to the National Institutes of Health.
Eye strain is uncomfortable and can lead to other negative effects, like headaches and fatigue. However, these negative effects are temporary. (Here’s how to prevent digital eye strain at work.)
Reading in the dark will also make your late-night novel binges more challenging to enjoy. A study in the Journal of Human Factors and Ergonomics Society found that dim lighting leads to less contrast between the light page and the dark letters, and this low contrast slowed down readers and reduced reading comprehension. Older adults struggled with low contrast even more than younger adults.
But as for your long-term vision, reading in the dark won’t make things worse (or better). If you’re worried about protecting your eyesight, develop good eye-preserving habits: quit smoking if you need to, eat a nutritious diet with lots of fresh fruits and vegetables, take out your contact lenses at night, and wear sunglasses and hats on sunny days. These healthy lifestyle habits can also reduce your risk of macular degeneration and diabetic retinopathy.
That said, giving yourself a bit more light might be in your best interest. In addition to reducing headaches and eye fatigue, you might even read faster and finish that chapter before having to call it a night, simply by lighting up your page.
Five vision myths. American Academy of Ophthalmology, 2012. (Accessed on April 9, 2018 at https://www.aao.org/eye-health/tips-prevention/five-vision-myths.)
Mitzner TL, Rogers WA. Reading in the dark: effects of age and contrast on reading speed and comprehension. Hum Factors. 2006 Summer;48(2):229-40.
Safeguarding your sight. Cambridge, MA: Harvard Medical School. (Accessed on April 9, 2018 at https://www.health.harvard.edu/healthbeat/safeguarding-your-sight.)
Vreeman RC, Carroll AE. Medical myths. BMJ. 2007 Dec;335(7633):1288-1289.