What happens in nearsightedness?

Nearsightedness (myopia) is the most common vision problem in children and teens. Distant objects are hard to see clearly, but close objects can be seen perfectly.

It usually appears in children at age 5 and progresses throughout childhood and adolescence. Although genetics is one of its main causes, there are ways to prevent nearsightedness.

What happens in nearsightedness?

Normally, light focuses precisely on the retina at a place called the focal point. In nearsightedness, the eye is longer from front to back than a normal eye, which causes light to focus in front of the retina instead of directly on it.

This makes it difficult to see objects that are far away, even though close objects appear clear. The main symptoms of nearsightedness include:

• Blurry vision or difficulty seeing distant objects.
• Headaches caused by tired eyes.
  
• Needing to squint to see things clearly.
  

The usual signs in children are:

• Constantly squinting.
• Rubbing the eyes often.
  
• Blinking excessively.
• Not noticing distant objects.
  
• Moving closer to screens, boards, or books.

To treat nearsightedness, you can wear glasses or contact lenses that counteract the increased curvature of the cornea or excessive length of the eye.

Another option is surgery, such as LASIK eye surgery, laser-assisted subepithelial keratectomy, and photorefractive keratectomy.

In general, these procedures use a laser to reshape the cornea. However, you may still need to wear glasses or contact lenses after surgery.

Impact of screen time

A relatively recent phenomenon that is one of the risk factors for nearsightedness is prolonged exposure to screens and digital devices. Using these devices requires close-up work while also limiting the time children spend outdoors.

Generation Z, also called “digital natives” (those born between 1995 and 2000), has been found to be the most nearsighted generation.

Specialists say that this is due to the growing use of mobile devices and digital screens, including during hours spent studying. Young people who leave school at age 17 are thought to have better vision than college graduates.

For this reason, people are encouraged to teach children different ways of entertaining themselves—without screens. Although using electronic devices is not necessarily a cause of nearsightedness, using them too much is harmful.

The recommendations for screen time in children are: from ages 0 to 2, no screen time; from ages 2 to 5, one hour of screen time a day; and from 5 to 12, a maximum of 2 hours of screen time a day.

Sources: National Library of Medicine; Mayo Clinic; National Eye Institute.