Blue light and screens: a danger to eyesight or just a myth?

With the digitalization of our daily lives, our eyes are more than ever exposed to blue light from screens. Smartphones, tablets, computers and televisions are all part of our environment, raising questions about their impact on visual health. But what do the experts really say? Let's decipher the true from the false.

1. Blue light tires the eyes

✅ True!

Screens emit a significant amount of blue light, a high-energy light wave that penetrates deep into the eye. Prolonged exposure can lead to visual fatigue, known as computer vision syndrome (CVS), with symptoms such as dry eyes, headaches and blurred vision.

2. Blue light is responsible for retinal damage

❌ Quite wrong!

While some laboratory studies have shown that intense exposure to blue light can damage retinal cells, exposure levels from everyday screens remain well below the danger threshold. In comparison, blue sunlight is far more powerful.

3. Blue light disrupts sleep

✅ True!

Exposure to blue light in the evening suppresses the production of melatonin, the sleep hormone, delaying sleep onset and altering sleep quality. That's why we recommend limiting the use of screens to at least one hour before bedtime, or using anti-blue light filters to sleep better. Yes, we know, it's hard to turn off all your screens before midnight, but your brain will thank you!

4. Anti-blue-light goggles are effective

✅ Partially true.

Blue-light-filtering glasses can reduce eyestrain, but their effectiveness in improving sleep quality and preventing retinal damage remains controversial. They are particularly useful for people who spend long hours in front of a screen.

5. There are solutions for preserving your eyesight on screens

✅ True!

Adopting good habits can limit the harmful effects of blue light:

• Apply the 20-20-20 rule: every 20 minutes, stare at an object 20 feet (6 meters) away for 20 seconds (even if it's just to stare at the office plant).
• Adjust screen brightness and contrast
• Use "visual comfort" or "night light" modes
• Blink regularly to prevent dry eyes

Blue light from screens is not intrinsically "bad", but excessive exposure can affect visual comfort and sleep. The ideal solution is to adopt preventive measures to reduce eyestrain and promote restful sleep. Don't throw your screens out of the window - use them in moderation!

By Candice Lhomme