You have probably felt it that after a bad night’s sleep your eyes feel dry, gritty and tired. It turns out your eyes and your sleep are far more connected than most of us realise, and light is the thread that ties them together.
While it doesn’t take much to look after both, we spoke to ophthalmologists to understand how our eyes help set our body clock, what late-night screens do to our sleep, and the easy everyday habits that keep our eyes comfortable.
Your eyes help tell your body what time it is
I guess our eyes do more than just help us see. According to Opthamologist Dr. Supriya Sriganesh, Nethradhama Super Speciality Eye Hospital, they help set the rhythm of our day too by telling the body what time of day it is. She says that “there are special cells in the retina, called intrinsically photosensitive retinal ganglion cells (ipRGCs) that sense light, and gauge whether it is day or night, and pass that information to the brain’s internal clock.
“These cells contain melanopsin, a photopigment, which helps detect ambient light and also regulate melatonin secretion and the sleep–wake cycle,” she adds.
Dr. Rekha, Consultant - Ophthalmology, Fortis Hospital, Bengaluru, makes a similar point. “Our eyes are in close contact with the body’s internal clock, the circadian rhythm, which controls the sleep-wake cycle,” she says. Sufficient sleep, she says, allows the body to recover, and a regular sleep pattern and healthy light exposure can contribute to visual comfort and the overall health of the eyes.
What poor sleep does to your eyes
By now we know that sleep does play an important role when it comes to eye health but let’s find out what exactly happens to your eyes when you are asleep or what insufficient sleep does to them.
“During sleep, the closed eyes help to limit the contact of the eyes with environmental irritants and allow for the recovery of the tear film,” Dr. Rekha explains, adding that poor or insufficient sleep can lead to dryness, redness, eye strain and difficulty focusing the next day. “Regular sleep patterns can help reduce these symptoms and encourage comfortable vision,” she says.
When the sleep cycle is disturbed, Dr. Supriya points out, the ocular surface is disturbed which then causes gritty eyes (where the eyes can feel scratched or irritated without any debris present), tiredness, and blurring of vision.
Morning light is your friend
While many of us have been told that morning walks are great for health, mornings can give us much more than just a breath of fresh air and empty roads. According to the experts, exposure to morning light can support eye health.
“The timing and intensity of light exposure matter for both sleep and eye health,” Dr. Supriya says. “Bright daytime light, particularly natural outdoor light, helps synchronise circadian rhythms,” she explains.
“Exposing yourself to natural daylight in the morning helps reset the sleep-wake cycle, resulting in improved sleep at night,” says Dr. Rekha. “Daylight outdoor time also helps to give the eyes a break from long hours of close work, like reading or using electronic devices,” she adds.
Late-night screens and sleep
When have screens done us any good? Besides our parents, even experts do not appreciate the habit of looking at screens late at night. Going by the rule book, it is also advised to not look at a screen an hour before sleeping. Experts say that exposure to bright light late at night, especially blue light emitted from devices, may suppress melatonin and delay sleep timing.
“Screens don’t automatically harm the eyes, but long hours can lead to digital eye strain and dryness, especially when we blink less often,” Dr. Rekha explains.
Easy habits that make a difference
A few simple habits go a long way to support eye health. Apart from stepping outside in the morning for a few minutes, Dr. Supriya advises to look away from screens periodically and close your eyes for some time between tasks if devices are a big part of your daily schedule.
“Make sure to lower screen brightness in the evening and give yourself a buffer before bed,” Dr. Sriganesh adds. “Remember, good sleep hygiene is important to feel refreshed and ready for the world the next day,” she says.
“Sleep for seven to nine hours and go to bed at the same time every day. The 20-20-20 rule, which means looking at something 20 feet away for 20 seconds every 20 minutes, can help relieve digital eye strain,” she explains.
When to get your eyes checked
Despite your best efforts, if dryness, itchiness, redness or blurred vision persists, an eye check-up is always the sensible next step. Healthy sleep and balanced light exposure are practical ways to help support eye comfort and well-being. If you have dryness, blurred vision or discomfort that persists after making these changes, consult an eye specialist for appropriate advice.