Watching cell phones without turning on the light is harmful to eye health, mainly because it is easy to cause visual fatigue, as well as cause myopia growth. Watching cell phones without turning on the light is an unhealthy habit that many people have, and watching cell phones in a dark environment will more easily cause visual fatigue, as well as cause myopia to grow, thus jeopardizing eye health. When you look at the cell phone without turning on the light, the contrast between the surrounding environment and the brightness of the cell phone screen is too large, and it is easy to stimulate the eyes to cause visual fatigue, and at the same time, prolonged visual fatigue will further lead to the aggravation of myopia. Therefore, patients must develop good eye habits, when watching cell phones to ensure that the eye environment appropriate light, and should avoid the use of electronic products for a long time without interruption, after a period of time to pay attention to rest.