Blue light, known as High Energy Visible (HEV) light, is the sort given off by laptop, tablet and phone screens.
Apparently blue light can induce oxidative stress in the skin, and oxidation is the gradual damage to the skin that produces free radicals — unstable electrons which accelerate the skin's ageing process.
Blue light has a longer wavelength than UVA and UVB light, therefore it can penetrate skin more deeply and damage the collagen and elastin that keep skin firm and supple. If the damage carries on long enough, it results in wrinkles.
On average we get more than six hours of HEV light exposure each day, so an effective defence is paramount. Moreover, HEV weakens the skin's protective barrier and activates melanin production, which causes pigmentation. But most consumers are unaware of the damage HEV light is capable of doing to the skin.
Limiting screen time benefits your health as well, as blue light suppresses production of the sleep hormone melatonin. See if your phone settings allow a "yellow light" option and fix a blue-light protector to your devices.