I looked up some information, and this statement is indeed reliable:

Spending 1.5–2 hours outdoors every day can significantly reduce the incidence of myopia in children. There's a well-known saying in ophthalmology circles: the most effective "medicine" to prevent myopia isn't atropine, but the sun.
Mechanism 1: Bright light → Dopamine release → Inhibits eye elongation,
Mechanism 2: Outdoor environment provides a wide range of viewing distances.
So protecting your eyes = 20-20-20 rule + 2 hours outdoors:
Every 20 minutes of near work,
Look at something 20 feet (6 meters) away,
For 20 seconds,
Plus at least 2 hours outdoors daily.
This combination is currently recognized as the most effective habit for myopia prevention. I recommend everyone to keep track of it for themselves and their children.