Light emitted by the sun and personal electric devices contain significant amounts of high-energy, short-wavelength blue light. Ultraviolet (UV) light contains more energy than blue light but is it absorbed by the cornea and lens thus limiting retinal exposure. Visible blue light may potentially be harmful to the retina after extended exposure. Children may be at a higher risk for blue light retinal damage than adults because the juvenile lens absorbs less short-wavelength light than the adult lens allowing more blue light to reach a child's retina. After a life time of exposure the risk of cataracts and macular degeneration is increased. At this time, the long term consequences of blue light exposure in children is not well understood. All children should have sun protection in the form of dark sunglasses that filter UV light to reduce any risk of retinal and eye damage.
Although the light emitted by personal electronic devices is not bright enough to damage the retina it is able to alter the circadian rhythms that affect sleep and degrade sleep quality and impair alertness the following day. Therefore, it is recommended to limit the use of personal electronic devices before bedtime especially in children.
(excerpted from Winter 2017 Eye on New Jersey)