NEW YORK, Nov 28: For many baby boomers and anyone over 60, the warning to avoid sitting too close to the television was a common piece of advice from their mothers. It turns out, there is some truth to it. Prolonged close viewing of screens can affect eyesight, but the real risk now comes from smartphones, tablets, and computers rather than traditional TVs.

"Your mother was right, but the screen has changed," said Marcela Estrada, an assistant professor of ophthalmology at the University of California at Davis. "And today, every kid has a screen."

Children, particularly those between the ages of 7 and 15, face the greatest risk of developing eye problems like myopia, or nearsightedness. However, both younger and older adults may also experience eye issues.

Since large flat-screen TVs replaced small cabinet TVs, the risks from television screens have decreased. Large screens tend to make it harder to see everything clearly when sitting too close, prompting viewers to maintain a safer distance. However, smartphones, tablets, and computers are often held just an arm's length away, which is too close for comfort, experts say.

“Everybody in school and at home are now on their phones and tablets, and more time spent doing this ‘near work’ can increase the incidence of myopia,” said Masih Ahmed, an assistant professor of ophthalmology at the Baylor College of Medicine. "This is occurring mainly in kids because that’s when the eye is developing the most."

Myopia is a condition where individuals can see objects clearly up close, but struggle with those further away. If left unchecked, this can lead to serious eye problems over time.

When we look at screens up close, our eyes turn inward, causing a muscle behind the iris, the ciliary body, to contract. This changes the shape of the eye’s lens, leading to myopia.

“The eye lens gets fatter,” Estrada explained. “When you consistently focus too closely, the eye lens spends more time accommodating and changes its shape to focus the image on your retina. If you do this too much, you encourage your eye to grow too fast, which promotes myopia.”

The process of the eye lens growing excessively can become problematic, particularly for younger children, as the eye continues to develop. “Your eyes stop growing between ages 18 and 25, so it’s especially important to pay attention to this issue in younger children,” said Daniel Cyr, a pediatric ophthalmologist at Stony Brook Medicine. "The younger they’re found to be myopic, the more likely they are to develop ‘highly’ myopic eyes. This extreme form of nearsightedness can lead to significant risks like vision loss, retinal detachment, cataracts, and glaucoma.”

In some cases, genetic conditions such as Stickler syndrome and Marfan syndrome may cause "high myopia," Estrada added. A family history of myopia also increases the risk. If one parent is myopic, the child is at a higher risk, and the risk is even greater if both parents are myopic.

Myopia cannot be reversed or cured, but it can be corrected with glasses or contact lenses. For adults, laser surgery is also an option, according to the National Eye Institute.

Even young adults in their early 20s can experience the progression of myopia with excessive near work, Estrada noted. In individuals over 40, presbyopia, or the difficulty in focusing on nearby objects, can develop. This age group may experience eye strain, fatigue, and double vision, which is caused by the inability to maintain near focus.

Preventive measures

To reduce the risk of myopia or its progression, parents can take several steps, experts advise:

- Limit non-school screen time to one hour or less per day. “This may be tough for a teenager, but the important time is during the younger years when you still have some control over their use of these devices,” said Cyr.

- Encourage children to hold screens at least an arm's length away from their eyes, Estrada suggested.

- Place tablets in heavy cases to make them harder for children to hold for extended periods, or set them up on stands or desks, Estrada recommended.

- Ensure children spend time outdoors. "Two hours a day outside is a good preventive measure against myopia," said Estrada. Growing evidence suggests that outdoor time may help prevent myopia onset, though it may not slow the progression in children who already have myopia. Experts are unsure why daylight helps, but it could be because being outdoors allows eyes to relax and work less, Estrada said.

Additionally, children should receive at least one professional eye exam before reaching kindergarten. “With infants, we have tools that take a picture of a child’s eye to measure refractive errors, which help determine whether the eye needs correction,” Cyr said. “If they fail, they should go to a pediatric ophthalmologist.”

The bottom line is that sitting too close to screens can harm your eyes, particularly in children. Some adults may experience eye strain or double vision. Experts recommend that children should avoid excessive screen time and spend time outdoors to protect their eyesight.

“The sweet spot where high near tasking probably won’t harm your eyes, other than dry eye symptoms, is between the ages of 25 to 45. Outside of that, don’t sit too close to the TV or screen,” Estrada advised.