Transcript for Rise of kids' vision troubles leaves doctors stumped
The number of children with vision problems is on the rise and eye doctors are concerned more children are needing glasses at younger ages. Diane Macedo is back and, Diane, it is believed that screens are at least partially to plane for this. That's right. They say the number of kids nearsighted has more than doubled. Now doctors are saying it's not just about screen time but also sun time. At just 5 years old little reed Mckay's eyesight started going downhill. He had had quite a change in his prescription at that point. I thought, well, this isn't a great sign. Reporter: He is part of a disturbing trend. In the past decade doctors have seen a steep increase in the number of children who need corrective lenses. In the early 1970s, roughly 20% of children were nearsighted or had trouble seeing far away. Today, that number has more than doubled to 42%. Dr. Katherine says for optometrists it's an alarming mystery. It's not just an annoyance. There's a higher risk of cataract formation and glaucoma so big deal and potentially going to affect the vision long term. Reporter: But they do have some ideas. Excessive screen time could be a culprit and there's also lack of outdoor time since sunlight is known to help table lyze vision. No matter the cause, experts are Once it starts it's really tough to say it's going to reverse. It usually doesn't. Reporter: There are treatments to help curb the new trend. Some doctors are using eye drops from a medicine used originally as a nervous system blocker which slows down the development of nearsightedness. Others swear by the use of bluelight glass, glasses that block the blue light emitted by screens that may harm eyesight. Reed has tried a relatively new therapy called orthok. For three year he's been wearing hard contact lenses that reshape his eyes as he sleeps. Now it's just like 20/20 and there's nothing bad. He's done really well with it. We've seen really good results. His vision is great. Now, doctors say one tip implement 20-second screen time breaks and get them to look out the window for 20 seconds every time they finish a level but, everybody, get outside and play. Don't look outside actually go outside. All right, Diane, thank you so much for that.
This transcript has been automatically generated and may not be 100% accurate.