Stop playing with your phone before bed, or you might actually go blind! Beware of this disease →

What is your bedtime ritual? Many people may lie on a comfortable mattress, pick up their phones, read the hot news, watch short videos, play small games, reply to chat messages, browse Moments... When their minds are tired and their eyes are tired, they fall into a drowsy sleep.

If you do these things while sitting with the lights on, it's fine. But if you do these things while lying down with the lights off, it can easily lead to dry eyes, sore eyes, eye fatigue, and worsening myopia ... In addition, there will be a "thief" who will come to your door quietly...

This "thief" is glaucoma .

When you do these things night after night, it will steal your vision quietly - the normal field of vision of one eye is a 120-degree sector. The field of vision of one eye of a patient with chronic glaucoma may eventually shrink to a circle the size of a coin, which is called "tubular vision" in medicine - it is equivalent to rolling a piece of paper into a hollow tube and placing it in front of one eye. When one eye looks at the world through the hollow tube, it sees only the size of a coin.

If you want to see a wider field of vision, you have to turn your head. As glaucoma progresses, this field of vision will become smaller and smaller, until you can't see anything.

Why does turning off the lights at night and looking at your phone cause glaucoma? This starts with the cause of glaucoma.

01

The direct cause of glaucoma is high intraocular pressure

There is some liquid inside our eyes called aqueous humor , which is metabolized and flows inside the eyes. The aqueous humor is produced in the posterior chamber, flows from the posterior chamber through the pupil, then flows to the anterior chamber, and then flows out from the corner where the anterior chamber and pupil meet (chamber angle).

You can think of it as the aqueous humor entering from the water inlet and flowing out from the water outlet. According to physics knowledge, we know that the flow of liquid will generate pressure. This flow of aqueous humor also creates a certain pressure on the surrounding eye accessories, including the retina. This pressure is the intraocular pressure .

If the intraocular pressure of the human eye is maintained within the normal range of 10-21 mmHg , there is no problem. However, if the outflow of aqueous humor is blocked due to various reasons, the intraocular pressure will rise, and the pressure on the appendages of various parts of the eye will increase, which may cause functional damage.

For example, if the optic nerve on the retina is subjected to high intraocular pressure for a long time, it will atrophy. Optic nerve atrophy causes the optic nerve to not work normally, and a person's vision will deteriorate and the field of vision will narrow.

Therefore, the most direct cause of glaucoma is excessive intraocular pressure due to various reasons.

02

Turning off the lights and playing with your phone may increase eye pressure

Why does playing with your phone with the lights off cause increased intraocular pressure? In other words, why is the outflow of aqueous humor obstructed when playing with your phone with the lights off?

This is because in a dim environment, the pupil of the eye will automatically dilate in order to see objects clearly. The pupil is a small round hole with the iris outside the hole. When the pupil dilates, the iris is squeezed and accumulates at the outlet of the aqueous humor (angle of chamber), so the outflow of aqueous humor is more or less obstructed.

So the complete logical chain is: turning off the lights and playing with mobile phones will lead to obstruction of aqueous humor outflow, which in turn will lead to increased intraocular pressure and finally cause glaucoma.

But not all people who turn off the lights and play with their mobile phones will eventually develop glaucoma.

If the anterior chamber of a person's eye is relatively large, then after the aqueous humor flows into the anterior chamber, although the outflow is blocked, there is enough space in the anterior chamber to accommodate the "unsmooth" aqueous humor, so it is not a big problem.

For example, in some people's eyes, the angle of the chamber is very open, so even if the iris accumulates there, it will not block the water outlet.

Clinically, it is found that people who play with their phones when the lights are turned off and eventually develop glaucoma are more likely to have a small anterior chamber area and a narrow angle. But if you don’t go to the ophthalmologist for a checkup, you don’t know whether your anterior chamber area is large or small, or whether your angle is wide or narrow, right? I used to play with my phone when the lights were turned off, but suddenly one night, I had an acute glaucoma attack...

03

Acute glaucoma is dangerous, chronic glaucoma is hidden

Glaucoma, cataracts and macular degeneration are listed as the three major types of blinding eye diseases . The number of patients is very large. On average, each person has a 2% to 3% chance of developing glaucoma in his or her lifetime.

Depending on the patient's age, glaucoma can be divided into congenital glaucoma (0-10 years old), juvenile glaucoma (11-35 years old), and adult glaucoma (after 35 years old).

Among them, adult glaucoma accounts for the vast majority, and the onset age of adult glaucoma is mostly over 45 years old. However, in recent years, there has also been a trend of younger age groups . For example, as mentioned earlier, young people who often turn off the lights at night to play with their mobile phones increase their risk of glaucoma.

According to the course of the disease, glaucoma is divided into acute glaucoma and chronic glaucoma . Acute glaucoma is a very dangerous eye disease, and the symptoms are sudden headache, eye pain, red and congested eyes, blurry vision, as if through a layer of fog, rainbow circles around lights, photophobia, tearing, and nausea and vomiting.

Once acute glaucoma occurs, it progresses very quickly, and can cause complete blindness within 24 to 48 hours. Moreover, acute glaucoma can recur repeatedly, gradually turning into chronic glaucoma, and eventually leading to visual field loss and blindness.

Chronic glaucoma is highly hidden and the patients themselves are unaware of it.

About 50% of patients in developed countries do not know that they have glaucoma, while 90% of patients in developing countries do not know that they have glaucoma, and have never even heard of this eye disease. When the symptoms of the eyes become obvious, they go to the hospital for a checkup to find out, but it is often too late at this time. Glaucoma has already entered the middle and late stages, delaying treatment.

04

Common causes of glaucoma

There are many common causes of glaucoma. One type is internal causes, which are organic problems of the eyes , such as short axial length, small cornea, shallow anterior chamber, narrow chamber angle, etc.

The other type is external factors, such as staying in a dark environment for too long , turning off the lights to watch TV, movies, mobile phones, etc., which will cause pupil dilation and increased intraocular pressure; wearing tight clothes and corsets, especially collar buttons, ties, and bow ties that are too tight, and bras that are too tight; lowering your head or bending over for a long time, drinking a large amount of water (more than 500 ml) at one time , may all lead to increased intraocular pressure.

It is generally believed that among the external causes of glaucoma, there is a large category called psychosocial factors . Excessive emotional fluctuations, such as excitement, agitation, anger, sadness, depression, etc., will cause increased intraocular pressure; work pressure, family conflicts, changes in living environment, and excessive physical fatigue may also bring about emotional fluctuations, which in turn affect intraocular pressure.

05

How to prevent glaucoma

To prevent glaucoma, it is important to avoid factors that cause increased intraocular pressure as much as possible .

You can maintain a regular life, get enough sleep, combine work and rest, maintain a stable mood, a good mood, a balanced diet, and moderate exercise. In addition, avoid turning off the lights to watch TV, movies, and mobile phones, avoid wearing tight clothes, avoid bowing your head or bending over for a long time, and avoid drinking a lot of water at one time.

If you have underlying systemic diseases, such as diabetes, hypertension, etc., you must properly control the condition and have regular eye checks (once a year).

Glaucoma is like a car without a reverse gear. Although it cannot reverse and cannot be cured, it can slow down and brake. The vast majority of glaucoma patients can be treated with active medication and surgery to reduce intraocular pressure to a normal range, protect the optic nerve, and maintain good vision and visual field.

March 6 is World Glaucoma Day. Not only on this day, we should also take special care of our eyes at other times. When symptoms of eye discomfort appear, we must go to a regular hospital in time to ensure early detection and early treatment, so as to minimize the harm of glaucoma and other eye diseases to eye health.

Author: Zeng Xinyue

Reviewer: Jia Changkai, deputy chief physician, Xiamen Eye Center, Xiamen University