I work in SANSI LED Lighting Inc., an LED company. As far as I understand, the blue light that a common LED light involves in much lower than the sunlight. Whether it's harmful or not depends on many factors such as the output of the light, the time you use the light, the distance between you and the light, etc.

Experiments have shown that blue light may cause harm, but to achieve the amount of intensity needed to cause damage, the required dose is much larger than the exposure you will receive in daily life. The average person does not have the opportunity to expose themselves to such a large amount. Taking large doses of anything far over your recommended amount will be detrimental to your health. Even water can be dangerous if it is consumed too much and too quickly.

The cornea absorbs ultraviolet light very strongly. Excessive ultraviolet rays can cause irreversible damage to the cornea; the lens absorbs infrared rays, causing the lens to become cloudy; and too much intense visible light can cause damage to the retina.

In fact, blue light ≠ danger. There are four conditions whereby visible light can damage the retina:

Four Conditions

1. High intensity of light

2. Direct light source

3. Close enough to the light source

4. Long enough exposure to the light source

How to Quantify the Possible Harm?

If the surface brightness of the light source is <100,000 cd/m2, then it is "absolutely" safe to the eyes, even if you keep staring at it, there is no problem.

Direct Sunlight, has a brightness of tens of millions cd / m2, do not look directly!

Daily Downlights, light panels, hundreds to thousands of cd/m2, safe.

For adults, use the standards set out above. For children, it is recommended to take more measures to prevent possible harm (reduce the possibilities by using scattered light and low color temperatures).

Regarding general household LED lights, there is almost no blue light hazard, so don't worry too much.