Many individuals habitually turn off the lights before bed to relax by watching television, browsing on their phones, or using computers. Viewing a screen in an excessively dark environment forces the eyes to work harder than usual, leading to increased discomfort.

According to Doctor Hoang Quyet Tien from the Medical Information Center at Tam Anh General Hospital, in low-light conditions, constantly moving images and fluctuating light intensity from screens cause eye strain and fatigue. High-energy, short-wavelength light emitted from screens can damage retinal cells.

The habit of watching television and phones in the dark can affect visual health. Photo: Thai Thanh

The eye adjusts the amount of light entering it through the pupil. In bright daylight outdoors, the pupil constricts to reduce light intake. In darkness, the pupil dilates to absorb more light. However, television and phone screens are strong light sources with constantly changing intensity, forcing the pupils to repeatedly constrict and dilate to adapt. This prolonged process can lead to eye fatigue, pain, or difficulty concentrating. The effort to focus on clear images in the dark inadvertently reduces blinking frequency, making the eyes prone to soreness, dryness, and irritation.

When the pupil and iris sphincter muscle dilate, blue light (wavelengths 380-500 nm) from televisions and phones easily penetrates the cornea and lens, deeply affecting the back of the eye and causing retinal damage, particularly to the retinal pigment epithelial cells, according to Doctor Tien.

Blue light from electronic device screens can damage retinal cells. Photo: Eco Pharmaceutical Joint Stock Company

The prolonged habit of using electronic devices in the dark is a factor increasing the risk of macular degeneration and computer vision syndrome (CVS). Patients often experience symptoms such as dry eyes, burning, itching, a foreign body sensation, light sensitivity, watery eyes, and temporary blurred vision. Systemic symptoms include headaches, neck, shoulder, and nape pain, and a heavy sensation around the eye sockets.

Individuals with severe refractive errors, retinal vascular diseases due to diabetes, hypertension, or glaucoma, who frequently use electronic devices in dark spaces, face dangerous complications like retinal hemorrhage and even blindness.

To protect your eyes, Doctor Tien advises against using electronic devices in a completely dark room. It is recommended to add ambient lighting in the surrounding area or in the same direction as the television to reduce the contrast between the bright screen and the dark room.

Maintain an appropriate distance between your eyes and the electronic device, depending on screen size. After every 20 minutes of screen time, allow your eyes to relax by looking at a distant object approximately 20 feet (6 m) away, closing your eyes, or massaging them for at least 20 seconds.

Beyond adjusting electronic device habits, a balanced diet also supports visual health, slows eye aging, and reduces the progression of eye diseases. According to Doctor Tien, supplementing with natural broccophane extract from broccoli can help increase thioredoxin. This small protein acts as a reducing antioxidant, protecting retinal and lens cells from harmful blue light. This extract may help alleviate uncomfortable symptoms of computer vision syndrome, such as dry eyes, blurred vision, and eye pain and fatigue.

Thai Thanh