Buzz
“Turn on a light! You’ll ruin your eyes!” Growing up, I heard this warning repeatedly, accompanied by the sound of a light switch flicking on, whenever my mom caught me engrossed in a book. My protests that I could see perfectly fine fell on deaf ears. Her reasoning was simple and firm: without proper lighting, I’d damage my eyes and risk losing my love for reading.
Despite its persistence, this belief is a myth with deep roots. In 1604, Johannes Kepler, the renowned Dutch astronomer and “founder of modern optics,” attributed his nearsightedness to excessive studying. From there, it’s easy to see how the idea that poor lighting worsens eyesight gained traction (though some speculate parents used it as a tactic to get kids to bed).
Regardless of its origins, the notion that reading in low light harms your eyes is false. Dr. Sunir J. Garg, a spokesperson for the American Academy of Ophthalmology (AAO) and a professor at Wills Eye Hospital in Philadelphia, confirms there’s no scientific basis to suggest dim lighting damages your vision or eye health.
“It’s less about safety and more about personal comfort,” Dr. Garg explains. In his own household, his wife reads at night using only her backlit e-reader or a desk lamp’s focused light. (He, on the other hand, prefers the even glow of overhead lighting.)
Despite their soft, squishy appearance (remember that iconic scene in Kill Bill: Vol. 2), our eyes are remarkably resilient. However, vision issues are still a serious matter. Keep reading—under any lighting you prefer—to uncover more insights.
Reading in low light does not damage your eyes—end of story.
To debunk the myth about reading in dim light, simply ask how a lack of brightness could harm the eyes. It’s not like eyes melt like ice cream in a poorly lit room, nor will you suddenly go blind mid-chapter (especially during the most gripping part of the book).
Often, those who caution against reading in low light suggest it could lead to refractive errors over time. These are vision issues categorized into four main types: myopia (nearsightedness), hyperopia (farsightedness), astigmatism (blurred vision due to irregular cornea or lens shape), and presbyopia (age-related difficulty focusing on close objects, often requiring reading glasses). These problems arise from changes in the eye’s shape, disrupting how light focuses on the retina. Most of these conditions affect close-up vision, which is most noticeable while reading.
Nearsightedness is the most prevalent vision issue globally and has been increasing at an alarming rate since the mid-20th century. Research predicts that more than half of the world’s population may have some level of myopia by 2050. In the U.S., cases rose from 25 percent in 1971 to about 40 percent today, with a 14 percent jump since 2000. The surge is even more dramatic in East Asia, where countries like China, Japan, Singapore, South Korea, and Taiwan report myopia rates of 80-90 percent among children and teens—a stark increase from 10-20 percent in the 1950s.
Part of this increase might stem from better awareness and availability of eye exams and glasses in developing countries, particularly for children aged 6 to 12, when many first require vision correction. However, even accounting for this, the surge in cases is too rapid to be solely attributed to genetics, which was considered the main factor in the 1960s and 70s.
Genetics continues to be one of the most significant indicators of nearsightedness, with research identifying more than 100 genetic markers associated with the condition. However, researchers note that children inherit not just genes but also habits from their parents. Some studies suggest that the time spent studying (or revisiting Harry Potter) raises the likelihood of developing myopia, particularly during elementary and middle school years.
That said, none of these studies have established a connection between nearsightedness and the level of lighting used during activities like reading, even at night. “From an eye health standpoint, there’s no evidence to suggest it matters,” Dr. Garg explains. “It ultimately comes down to personal preference and comfort.”
There’s no harm in using ample light—even blue light
When I read in bed, my desk lamp sits parallel to my eyes, often shining directly into them rather than above. When I asked Dr. Garg about this, he reassured me that my eyes are perfectly capable of handling the light without any issues.
But what if the direct light is blue light from an e-reader, tablet, or smartphone? “There’s minimal to no high-quality scientific evidence indicating that blue light from screens poses any harm,” he states. While blue light does influence our circadian rhythms, it’s worth mentioning that a frequently cited study found participants exposed to blue light at night fell asleep, on average, just 10 minutes later than the control group. (Other researchers argue the study’s lab conditions severely underestimated the amount of natural and artificial light most people encounter daily, potentially skewing the results.)
“Humans have been exposed to blue light for thousands, if not tens of thousands, of years,” Dr. Garg notes, “since blue light is a component of sunlight.”
He continues: “We’re exposed to far more blue light during a typical day outdoors than we would ever get from staring at screens for eight hours.” After all, a sunny day is roughly 100,000 times brighter than our computer screens. This means using dark mode or nighttime settings on devices isn’t harmful, but it’s unlikely to provide significant benefits either. And save your money on blue-light blocking glasses unless you enjoy spending on ineffective products. No judgment!
Avoid blue-light filtering glasses outdoors, as one compelling theory about the global rise in myopia suggests it’s linked to insufficient exposure to outdoor light. Numerous studies have demonstrated that children who spend more time outside develop less myopia. The exact reason remains unclear, though potential explanations include the brightness of sunlight compared to indoor lighting and the prevalence of close-up tasks indoors. Some experts even argue that light exposure might not be the primary benefit of outdoor time, but another factor entirely. This hasn’t stopped countries like Taiwan from mandating outdoor time for young children; one study found myopia rates in 5-6 year-olds in a Taiwanese city dropped by nearly 50 percent two years after the policy was implemented.
That said, it’s a good reminder to wear UV-blocking sunglasses and avoid staring directly at the sun when you step outside. Just a few seconds of sun-staring can cause temporary damage, while around 100 seconds can lead to permanent harm, with symptoms including light sensitivity, pain, blurred vision, and even blindness. Wearing UV-blocking sunglasses is as crucial as applying sunscreen.
Reading under any lighting can lead to discomfort, but it won’t cause harm
Regardless of the type of light, prolonged close-up tasks will inevitably result in eye strain—a broad term for various symptoms that arise from overworking your eyes. These symptoms may include:
blurred vision
tearing
dryness
headaches
neck, shoulder, and facial muscle pain
difficulty concentrating
burning or itching sensation in the eyes
A major contributor to eye strain is reduced blinking, which occurs when we focus intently. “If you watch a child playing a video game, they barely blink,” Dr. Garg explains. “Adults experience something similar.”
Blinking replenishes the eyes with tears that supply essential nutrients and oxygen to maintain eye health. Normally, we blink between 12 to 15 times per minute, but this rate can decrease by up to 60 percent while using a computer. Reading a book can reduce blinking even further.
While we’re not blinking, we’re also straining our eyes by keeping them fixed in one position for extended periods. Dr. Garg likens this to holding your arm out or standing in the same posture for too long.
Though dryness and fatigue sound unpleasant, they’re temporary issues with simple fixes and no lasting effects. Dr. Garg explains that repetitive eye strain, unlike repetitive strain in limbs, doesn’t cause cumulative or permanent harm. Additionally, not everyone experiences eye strain—it varies by individual and often worsens with age.
If your eyes feel dry after a few hours, there are two solutions: moisturize them and take a break. Start with artificial tears or rewetting drops to lubricate your eyes. Any brand works, but contact lens wearers should use drops designed for lenses, as others may blur vision. If you’re in a dry climate, a humidifier might help. This is more about personal comfort than necessity. For example, Dr. Garg uses humidifiers at home during Philadelphia’s dry winters to combat dry skin and eyes.
To rest your eyes, follow the 20-20-20 rule: every 20 minutes, focus on something at least 20 feet away for 20 seconds. This is like stretching your muscles during sedentary work to prevent stiffness. It also allows your eye muscles to relax from the slightly crossed position they adopt during close-up tasks. (And no, your eyes won’t get stuck if you cross them—another myth debunked.)
If dry eyes significantly impact your quality of life or work, Dr. Garg advises consulting an eye doctor. “The treatments available today are far superior to what we had even five years ago,” he notes.
The best way to protect your eyes is to maintain overall health
Ironically, we often notice the discomfort of eye strain more than the symptoms of many serious and irreversible eye conditions like macular degeneration, glaucoma, and diabetic retinopathy. “Many eye diseases don’t cause much pain, and some don’t lead to vision loss until they’ve progressed significantly,” Dr. Garg explains.
Eye screening recommendations vary widely, partly because those with corrective lenses typically require more frequent visits than those with perfect vision, as they need regular prescription updates. The AAO suggests a baseline eye exam at 40 for adults without symptoms or risk factors, while the American Optometric Association (AOA) advises annual exams for adults 18 and older with risk factors and biennial exams for those aged 18-64. Risk factors include:
family history of conditions like macular degeneration or glaucoma
high blood pressure
diabetes
racial and ethnic background, particularly for glaucoma
age (the CDC recommends biennial eye exams for adults 60 and older)
While regular eye exams are crucial, one of the most effective ways to care for your eyes is to follow general health practices. “What’s good for your entire body is also excellent for your eyes,” Dr. Garg emphasizes.
Avoid smoking altogether, or if you currently smoke, make quitting a priority. Incorporate a minimum of three portions of leafy greens and omega-3-rich foods, such as fish, into your weekly diet. Aim for around 30 minutes of moderate cardio, like a brisk walk, three times weekly. According to Dr. Garg, 'For the majority, these steps are sufficient to maintain overall eye health.'
There's no need to stress over the level of lighting while reading—unless you're looking to counter the concerns of a family hypochondriac. In that case, feel free to share this article with them.
