Before going to bed with a cell phone to play a game, brush WeChat or browse the news, has become the habit of many people nowadays. Unbeknownst to you, playing with your phone before bed not only affects your sleep, but staring at it for more than half an hour in the dark or in a low light environment can cause damage to your eyes, and in serious cases, may also induce glaucoma. In general, normal people blink about 20 times per minute, but when using a cell phone, the number of blinks per minute decreases because of excessive concentration, plus the light from the cell phone screen is more blinding after the lights are turned off, which can easily lead to a reduction in tear secretion and a change in tear composition, which can cause the corneal epithelium to detach in severe cases. Once the integrity of the tear film and corneal epithelium of the human eye is damaged, it will lead to the occurrence of dry eye disease. The most common symptoms of dry eye are foreign body sensation, uncomfortable dryness, burning and swelling, and photophobia. In addition, staring at a cell phone in darkness or low light for long periods of time can cause an increase in the burden on the eye’s regulatory system, leading to rapid myopia progression. In particular, excessive eye use in dim light may also cause prolonged pupil dilatation, blocking the circulation of fluid in the eye and triggering glaucoma. Glaucoma is currently one of the top blindness-causing eye diseases in China, with serious consequences. Doctor’s tip: Staring at a cell phone for more than half an hour in a dark or low-light environment can cause damage to the eyes and may induce glaucoma in serious cases. So do not use your eyes excessively in the dark environment. Also, if there is any eye discomfort, please seek medical attention and use medication under the guidance of a doctor!