A 2012 Spanish study found that LED radiation can cause irreversible damage to the retina. A 2019 report from the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) warned of the “phototoxic effects” of blue light exposure, including an increased risk for age-related macular degeneration.

Light is a transverse, electromagnetic wave that can be seen by the typical human. The wave nature of light was first illustrated through experiments on diffraction and interference. Like all electromagnetic waves, light can travel through a vacuum.

The two most successful theories of light were the corpuscular (or particle) theory of Sir Isaac Newton and the wave theory of Christian Huygens. Newton’s corpuscular theory stated that light consisted of particles that travelled in straight lines.

Three models of light

• Ray model of light.
• Wave model of light.
• Quantum model of light.

The amount of blue light from electronic devices, including smartphones, tablets, LCD TVs, and laptop computers, is not harmful to the retina or any other part of the eye.

A red light color is best for sleep because it has a low color temperature, far lower than regular sunlight. You can be immersed in red light at night without giving your body a jolt and altering your internal clock as blue light does.

All artificial light, including LEDs, fluorescent bulbs and incandescent bulbs, can interrupt normal sleep patterns. The body’s biological clock works in rhythms that are set by the amount of light and dark the body is exposed to. This is called the circadian rhythm.

Incandescent bulbs have a filament that emits excessive heat, the light sources can ignite a fire on overheating, but as LED lights produce light at a lower temperature, they don’t catch fire as easily.

“Blue lighting accelerates the relaxation process after stress in comparison with conventional white lighting,” the researchers confidently declared.