A senior VP at LGD recently declared in the IMID Display Business Forum in Korea that according to measurements done by the company, LCD screens emit 3.1 times more blue light than OLED screens. The measurements were done 120 cm away from TVs, 60 mm from monitors and 30 cm from smartphones (TVs are larger and emit more blue light than other types of screens).
Blue light is high energy visible light, widely acknowledged to bear harmful effects like discomfort to the eye and damage to the retina, as well as serve as a contributing factor to diseases such as cancer, diabetes, heart disease, obesity and insomnia. Children seem to have delicate retinas that are highly susceptible to the dangers of blue light.
In addition to all this, blue-light LEDs, which are a staple of LCDs, have been found to have a tendency to attract flying insects. A lot of them.